Question: I used my Capital One credit card to buy plane tickets for a trip to India through my neighbor, who is a travel agent. When I got the bill, I noticed I was also charged for the next customer's flights - which cost $2,400! My neighbor quickly realized that there had been a glitch in her computer, so together we contacted Capital One. The company asked us to fill out a dispute form. We did, but the charge hasn't been removed. Can you help? - Michael Ryan, Nine Mile Falls, Wash.

Answer: Since your travel agent copped to the error, this issue should have, under normal circumstances, been resolved relatively quickly. Ah, if only.

Turns out your forms got misrouted in Capital One's paper chain. The company's reps admitted to us that they dropped the ball. "We sincerely apologize," says spokeswoman Pam Girardo. The firm reopened the investigation, but the airline involved said it was too late for them to issue a refund. So Capital One covered the cost - crediting the $2,400 and refunding the $186 you'd shelled out in minimum payments on the charge. (You needn't have paid these, by the way, but more on that in a moment.)

Here's what you need to know to prevent such problems in the future: Rules set out by the Fair Credit Billing Act (FCBA) protect you from getting stuck with charges that aren't yours. If you dispute a charge in writing within 60 days of getting a statement, the card issuer must respond in 30 days to let you know it's investigating. The firm then has two billing cycles to correct the charge or explain it. Until that point, you don't have to pay the charge and you can't be reported to the credit bureaus.

If an issuer doesn't respond, as was the case with Capital One, you can contact the Federal Trade Commission (1-877-FTC-HELP), which may fine the issuer. You can also sue a non-responsive creditor for damages, attorney fees and finance charges. Fortunately, it doesn't often go that far, says Curtis Arnold of CardRatings.com; issuers are usually prompt to deal with such matters. And on the rare occasions when they aren't, threatening them with these actions - and invoking the FCBA - can get things rolling.

Tip: Read every credit bill carefully and dispute errant charges within 60 days of the statement date - in writing via certified mail.

So far Money Helps has saved readers $190,429.03

Having a financial nightmare? E-mail Donna Rosato at money_helps@moneymail.com.

--Reporting By Ingrid Tharasook