(MONEY Magazine) – Modern society, if you think about it, is a fragile balance between buyers and sellers. All the goods we need to live, work and enjoy life—cell phones, raincoats, milk, computers, hotel rooms, DVDs, potatoes—have a price, and if we don't pay it, we don't get the goods. We can't stay in the room for $50 if the hotel's rate is $250, and we can't decide to pay a quarter for milk instead of 79¢. In return, we expect stuff to work. If it doesn't—if the computer crashes, if the milk's sour—we get mad. Boy, do we get mad.

Why shouldn't we? After all, we held up our end of the bargain, and if justice is to be served, so should the seller. We want our money back. No, wait—not just our money back. We want more! For the inconvenience! Something for free! Another 10% off! More! May I speak with your supervisor?

Enter customer service reps. Complaining to them—or to anyone who sells you something, from a restaurant manager to a dry cleaner—can be an art form. Some people are just plain good at it. They always seem to be bragging about how they got a comped hotel room or two free months of cable.

Well, it's time for the rest of us. As it turns out, sometimes all you have to do is ask. According to Technical Assistance Research Programs (TARP), a consumer service research firm, for every person who files a complaint about a consumer problem, seven do not—but each of those seven tells nine friends about the problem rather than someone who could actually solve it. And those friends tell their friends. Meanwhile, it costs companies six times more to obtain a new customer than to keep an old one. It's usually in their interest to right wrongs.

But not every caller to the toll-free number gets the same restitution. To help you get more for your minutes on hold, MONEY asked veteran customer service representatives, retail and service managers, consumer advocates and self-described masters of complaining for their best advice on lodging a fruitful grievance. We came up with six basic rules of complaining—or kvetching, as they say in Yiddish—and then applied them to a dozen common scenarios. We can't guarantee that you'll get a free lunch every time, but you never know. So call, follow these rules, and demand that the offending company hold up its end of the bargain. Operators are standing by.

12 KNOTTY PROBLEMS, 12 EFFECTIVE COMPLAINTS

FLORIST You send flowers for a special occasion. They show up a day late

What to say: The florist will likely agree he blew it, but finagling a proper restitution may prove to be harder. Use a little drama—point out that the occasion (birthday, anniversary, dental-implant surgery) has passed and will never, ever happen again in all eternity, and that you spent good money to make a person feel special on that day. Then say simply, "What can you do to make this person feel special now?"

What to expect: For starters, a really big bouquet of flowers. Plus, the florist should relay a mea culpa to your intended, in the form of a phone call or a note or both. Brenda Robertson, v.p. of customer care for FTD.com, once stepped in to play cupid for a business traveler whose flowers didn't arrive in time for his girlfriend's birthday. "He wanted me to call her and tell her he loved her and he wished he could be with her," she says. Robertson made the call—and made sure a lot of fresh flowers arrived the next day.

DRY CLEANER You pick up your favorite sweater from the dry cleaner and discover that it has shrunk

What to say: The cleaner will likely try to shift the blame for the damage to the garment's manufacturer or, worse, you. "Twenty-one percent of the damage reported at the cleaners is caused by consumers; 10% is dry cleaner mistakes," says Alan Spielvogel, director of technical services for the National Cleaners Association (NCA), a trade group. Granted, those are the industry's own numbers, but they do suggest that it might not be the cleaner's fault. Tell the manager it's not about the cash—you can afford a new sweater. Then drop this inside info: If the business is one of the 3,500 members of the NCA, it can send the garment to the National Center for Garment Analysis (nca-i .com), where testing can determine the source of the problem. But that's costly. "Refunding your money is often more cost-effective than paying for the test," Spielvogel says.

What to expect: If the cleaner shrank your sweater, he must pay you for it, accounting for depreciation. "A sweater's expected life span is three years," Spielvogel explains. "So if the sweater is a year old and cost $100, the value depreciates by 33%." That entitles you to $67.

HOTEL You arrive at your hotel and don't have a room

What to say: Most hotel managers have the authority to make reparations on the spot, according to Jim Hartigan, senior v.p. of customer quality and support at Hilton. "You have a much better chance of reaching a resolution if you give the hotel team a chance to get it right while you're there," he says. Resolve the issue with an on-site manager immediately, not through the corporate offices later. Ask how, exactly, the hotel is going to make you feel first class.

What to expect: It's common for an oversold hotel to put you in a comparable room at another hotel and get you there comfortably. For mint-on-the-pillow service, the offending hotel should offer you a room upgrade plus a drink at the bar or a meal to restore that five-star feeling. Niki Leondakis, chief operating officer at Kimpton Hotels & Restaurants, says her concierges sometimes throw in theater or sports tickets if loyal customers are shut out. Finally, the hotel should be begging you to give them another chance: "I would provide a certificate for another night's stay," says Hartigan.

HAIR SALON At a salon, it turns out the advertised $40 haircut doesn't include basics... like blow-drying

What to say: Additional charges are common at both upscale salons and national chains. "High-end salons have specific people devoted to shampooing, coloring, styling and blow-drying, and the duties never cross," says Rob Saduski, salon consultant at Sally Hershberger Downtown in New York City, whose clients include Meg Ryan and Michelle Pfeiffer. You pay for each service individually. When you call for an appointment, he notes acidly, "the person answering the phone isn't going to run down a menu of prices." Joani Pattarozzi, 25, a paralegal in New York City, says she kvetched her way out of this very situation at a local haircutter: "The stylist started to blow my hair out, saying it would make it easier to finish the cut. At the end, they tried to charge me $68."

What to expect: Pattarozzi paid $35. "If we didn't tell you about the charges prior, we do take it off," says Dwight Sims, acting manager at the Vidal Sassoon salon in Miami Beach. If the establishment resists, embellish: "I may be checking out hairdressers for a girlfriend's wedding in a few months. What am I going to tell her about this place?"

CABLE SERVICE Your cable service goes out during the big game

What to say: When educational software editor Amanda Cunningham's HBO on Demand went AWOL for three hours in her Manhattan home, she called and demanded money back. "They offered to credit me for the time I was paying for the service and didn't receive it, which came to something like 79¢!" Cunningham, 28, thought she deserved more. Her argument to Time Warner: Customers pay for cable to watch certain programming. If it went out at 3 a.m., fine. Give me 79¢. But if I'm prevented from watching the very programming I'm paying to see, they have to do better.

What to expect: "They gave me two months of the service free," says Cunningham, a $16 value. Try asking for a premium cable channel free for a month—the cable company loses nothing, and it may see the gesture as a way to eventually sign you up for a higher-priced service.

PHONE BILL You're charged for a phone service you never use

What to say: When retired salesman Ray Nesbit, 65, called Southwestern Bell to argue about a charge for a three-way call, he gave the perfect reason why it should be removed from the bill: "I didn't know how to make a three-way call," says the Missouri resident. He told the rep to look at past bills for proof.

What to expect: Nesbit's charge was removed. "If we're able to identify that there hasn't been any usage of the feature, we can make an adjustment," says Cindy Rock, Sprint PCS senior v.p. of customer service.

The same tactic worked for Samuel Dyer, a Tennessee-based pharmaceutical executive. Having never made an international call before, he asked MCI to add international calling to his plan one month when he knew he'd be making overseas calls. The company agreed—but then charged him $1,500 anyway. "I said, 'I spend a lot of money with you. I pay $60 a month, and it never changes,'" says Dyer, 31. He proved the calls were atypical by pointing to past bills, and MCI conceded.

CREDIT-CARD FEES You're out of town and miss your credit-card payment deadline. The company charges you a late fee

What to say: "Gimme a break. I was away. I'm never late."

What to expect: We called five credit-card companies and asked if a late fee would be waived in the case that the cardholder was out of town and missed the due date. Four said they had no problem waiving the fee for good customers who are first-time offenders. A Discover rep said the company would waive it for a death in the family but not a vacation.

BAGGAGE DAMAGE After a long flight, you arrive at your hotel and notice that your luggage is damaged

What to say: To avoid dealing with this problem for the next month, deal with it in the next hour. Go straight back to the airport baggage-claim area and find a representative from your airline, says Jacquie Young, spokeswoman for American Airlines.

What to expect: Most airlines will offer to repair or replace the bag. Ask to have a repaired bag shipped to your home (some airlines ask you to return to the airport to claim it). If your luggage is too mangled for repair, the airline can hand you similar luggage from its own inventory. If you'd rather get a new bag on your own, some airlines, including JetBlue, will reimburse you. Others might offer perks, like a voucher for future travel or an extra helping of frequent-flier miles.

RESTAURANT At a top restaurant, you get slow service, a tough steak and the wrong drinks

What to say: The problem here isn't each little fine-dining flub, it's the overall experience. Explain to the maître d' that an evening at a nice restaurant is costly and the experience has to measure up. "Don't speculate on what sort of day the server might have had," suggests Greg Northrop, owner of Mud, a high-end Manhattan café. "It's your experience that matters, and you weren't satisfied by your experience." Ask if you can come again to make up for this time—and to see if the experience improves.

What to expect: "If a guest says, 'There was a screaming baby next to me and I was here to propose to my girlfriend,' I'd offer a gift certificate to have him come back," says Ed Gannon, the chef at Lure on Martha's Vineyard.

GYM MEMBERSHIP You're injured and can't work out at your gym, so you'd like a break from the monthly fee

What to say: Limp on over and speak to the general manager—the front desk can't help you with this, and forget the phone. Most contracts deny membership freezes; like cable and magazine companies, gyms depend on your steady flow of payments for their operating budgets. Tell the manager you understand it's a pain. "Unpredictability of cash flow, which includes membership freezes, is seen as a liability by the gym's lenders," says Kelly Miyamoto, who owns The Firm, a Minneapolis workout studio. "When somebody recognizes that challenge, it makes the conversation go much better." Bring a note from your doctor. Mention that you plan to return when you're healed.

What to expect: "If you're hospitalized or incapacitated, we'll sign off with the general manager's approval," says Edwin Vilbrun, an Equinox member-services rep. The gym might charge an administrative fee; don't argue unless it's excessive—most contracts require automatic withdrawals, and the gym will have to pay to suspend the bank's service. If all else fails, request a few free personal-training sessions or complimentary classes to even things out. That's far less costly for the gym, and the right freebie might even help with your rehabilitation.

MAGAZINES You keep getting renewal bills for magazines you've already paid for

What to say: "The belief is, Every magazine does this and they're not going to change just because I complain," says TARP's Goodman. Still, you need your mailbox back. Call the subscriber-services number on the bill or in the magazine. We had our names taken off six mailing lists within 20 minutes simply by asking.

What to expect: Less mail—and more time to read MONEY, of course.

MOVIES You're at the movies and the sound is muffled

What to say: Go to the manager right away and ask to come back another time. To save your evening, have dinner and return for a later show. David Reedy, a realtor in his late fifties living in Ohio, says he recently went to a movie that was so loud "the volume was vibrating my body." The manager said the sound was set according to the instructions on the reel and he couldn't change it—but he gave Reedy a refund.

What to expect: Free tickets. Or a long stare from a gum-chewing high school kid. You can't win 'em all.