SAN DIEGO -- A credit card offer is grabbing a lot of attention, and customers said it is too good to be true.

It promises a special deal if customers transfer other debt onto the card.

Now, many are finding out the offer has cost them a lot of money.

Some Citibank credit card holders thought they were getting a deal.

Instead, their minimum payments went from less than $170 a month to almost $420.

"They thought they were bargaining for debt consolidation at a lower interest rate, but you need the contract that comes with the credit card," said consumer attorney Gary Rudolph, of the Sparber, Rudolph and Annen law firm.

Rudolph said many consumers are getting stung by Citibank's alleged 'bait-and-switch' deal. Customers like Brad Hunt were attracted by the teaser rates, and he thought the rate of 3.99 percent would stay the same for the life of the loan.

Hunt said, "Come January, the terms of the agreement changed to a $10 monthly fee. That is $120 a year, and they changed the 2 percent monthly minimum payment from 5 percent of the balance of the monthly payment."

Hunt said the deal even included transferred balances, so he did just that -- and then the terms changed.

"Consumers need to be a little proactive and read what comes with the credit card," said Rudolph.

Rudolph said in this case, what is legal is far from ethical so consumers have to read the fine print.

"They may, probably do anything to lower their rate ... consolidate their debt and they may be easy prey ... that may not have existed in the past," said Rudolph.

He also warned consumers about the consequences of late payments. Often times the credit card agreement allows the bank to raise your interest rate when your payment is not in on time.

"Don't be afraid to call the credit card companies. Keep a record of your calls, send confirming letters to the credit card companies … for conversations, create your own file in case there's a problem," said Rudolph.

In a written response, a Chase spokeswoman said, "The changes impact less than one-half of one percent of our accounts on file. Chase is a responsible and careful lender. We constantly evaluate the risks and costs of funding credit card loans."

Rudolph reminds consumers that teaser rates are just attractive figures meant to interest card holders.

He said consumers should never sign the deal until they have read the material that comes with the card.