Have you ever ordered something online that was delivered damaged ' or never arrived at all? Or been double-billed by a merchant? Or spotted a charge on your credit card statement you didn't make? Most of us have.

Fortunately, the 1975 Fair Credit Billing Act protects your rights during such credit card billing disputes. It also outlines the process for contesting charges made to your account. Here's how it works:

First, FCBA protection applies only to "open-end" credit account transactions ' those involving credit cards or revolving charges (e.g., department store accounts). It doesn't cover installment contracts you repay on a fixed schedule, such as car loans.

Billing errors that are covered by the FCBA include:

* Fraudulent or unauthorized use of your credit card, whether it was stolen or merchants charged unapproved items to your account.
* Charges that list the wrong date or amount.
* Charges for goods or services you either did not accept or that weren't delivered as agreed.
* Math errors, such as being charged twice for a transaction.
* Failure to post payments or other credits.

(Note: Report suspected fraud immediately. By law, you're only liable for the first $50 in unauthorized charges; however, most card issuers waive that liability if you report the charges quickly.)

Review all billing statements carefully upon receipt because in order to be covered under FCBA rules, most disputed transactions must be reported within 60 days of the statement date on which the error appeared.

First, contact the merchant and try to resolve the dispute directly with them. If this good-faith resolution attempt doesn't work, you can escalate the process by filing a written report with your credit card issuer within the 60-day window.

The card issuer is then obligated to investigate the dispute on your behalf. They must acknowledge your complaint, in writing, within 30 days of receipt and resolve the dispute with the merchant within two billing cycles ' but not more than 90 days.

Send your letter via certified mail to the card issuer's billing inquiry address, not the payment address. Include your name, address, account number and a description of the billing error. Include copies of sales slips or other documents that support your position.

According to the Federal Trade Commission (FTC), you may withhold payment of the disputed amount and related charges during the investigation. In fact, many card issuers may voluntarily remove the charge until the matter is resolved since they are representing you, their client, in the dispute.

If it turns out your bill contains a mistake, the creditor must explain, in writing, the corrections that will be made. In addition to crediting your account, they must remove all finance charges, late fees, or other charges related to the error.

However, if the card issuer's investigation determines that you owe part ' or all ' of the disputed amount, they must promptly provide you with a written explanation. If you disagree with the investigation's results, you may further dispute your claim with the creditor, as outlined by the FTC at www.consumer.ftc.gov/articles/0219-fair-credit-billing. (That site also contains a sample dispute letter and other helpful FCBA information.)

If you believe a creditor has violated the FCBA, you may file a complaint with the FTC or sue them in court.

Hopefully, you'll never have a billing dispute that goes to these extremes. But it's good to know how consumer laws protect you, just in case.

Alderman directs Visa's financial education programs. To Follow Jason Alderman on Twitter: www.twitter.com/PracticalMoney