NEW YORK (CNN/Money) - U.S. soldiers and at least one congressman are complaining about an exclusive contract AT&T was granted to provide pre-paid calling cards for military personnel stationed in Iraq, and the prices they have to pay, according to published reports.

The Newark Star Ledger reported Sunday that many pre-paid AT&T cards bought in the United States and shipped to soldiers in Iraq allow only a fraction of the minutes promised on the cards. Even the cards bought in Iraq, which an AT&T spokesman said were a better bargain for the troops, cost between 19 and 21 cents a minute for a call, according to the paper.

Calling cards issued by competitors do not work at "AT&T Calling Centers" set up in Iraq, and no other company has been able to set up such call centers, according to the paper.

AT&T spokesman Nersesian said the company "took the financial risk, we took the operational risk, and we took the personnel risk" in building the system. He also said AT&T has donated over $6 million in prepaid phone cards to the troops.

But in a follow-up story in the paper on Monday, U.S. Rep. Frank Pallone, D-N.J., said he would ask the Defense Department to investigate the cards.

"AT&T should be required to provide a clear and straightforward system of calling time that will make it easier for our troops to call home," Pallone said in a statement. "It disturbs me to think that companies are more interested in making a buck on our soldiers in Iraq than providing the quality services they have been paid to provide."

The paper reported many soldiers complain more about the calling cards than they do about the other conditions and threats they face in Iraq.

It reported that on certain bases, military personnel are allowed to call home on phones linked to the Army's own internal Defense Switched Network at morale, welfare and recreation centers. Those calls can be as cheap as 4 cents a minute, and those using pre-paid cards can use them from different providers and get the full number of minutes promised on the cards. But they are restricted to only one 20-minute call a week on the system, according to the paper. And those calls are not available to all soldiers.

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