Credit cards are more than just a convenient way to pay for stuff; when you use one, you automatically get incredibly strong protections against most lousy-service scenarios and companies that sell faulty goods. The genesis of these protections is the federal Fair Credit Billing Act, a law that protects you from fraud by requiring credit card companies — not consumers — to deal with fraudulent charges. The law also provides important protections against billing errors.

What many consumers don't know is that the law also requires your credit card company to give you the chance to dispute charges and withhold payment for goods and services that you didn't accept or that weren't delivered as promised. This means that if you used a credit card to pay for something that isn't satisfactory, and you tried to work it out with a seller who won't budge, you can tell the company that issued your credit card you want to contest the payment and get your money back. Ditto for defective or undelivered products.

When you request a "chargeback," the seller gets the opportunity to protest it — possibly by claiming that you made no effort to resolve the matter, or refused to return the goods that you say are unsatisfactory, or that the goods are exactly what you ordered. But as a practical matter, sellers rarely succeed in reversing chargebacks. As long as you return the merchandise (or try to return it), or document the product or service defect (for example, by having a second auto repair shop correct a lousy repair and write up what they did), you're likely to win the dispute and get your money back. Sometimes credit card companies simply eat disputed charges to satisfy their customers, rather than launch an investigation.

We asked Checkbook members to share their credit card chargeback stories and got more than 100 responses, almost all of them success stories. Billing mistakes and cases of theft and fraud, in particular, were handled promptly — no surprise since laws clearly protect consumers from these types of problems. For disputed transactions related to lousy service or defective merchandise, credit card companies usually removed the charges quickly, with few or no questions asked. Sometimes credit card companies investigated, which took a month or two and some back-and-forth between customers and sellers, but customers almost always won.

A handful of members did share negative experiences. Sellers more often win disputes when they ask customers to sign contracts during the purchase process that include clauses such as "all sales final."

Since credit card issuers strongly desire to keep their customers happy, the protections they provide are in practice even broader than your rights under the law. For example, while the law states that you have to contest a charge within 60 days of receiving a bill, most banks that work with Visa and MasterCard give their customers 120 days to contest it, and on a case-by-case basis usually allow even more time — especially if you can document that you could not have known about the problem any sooner. And while the law protects you only for purchases in your home state or within 100 miles of your current billing address, credit card companies usually let you contest any charge. American Express, in particular, is well known by retailers to have a very generous policy toward its card users.

Similarly, debit card purchases aren't covered under the Fair Credit Billing Act. But when you pay with a debit card that uses the Visa or MasterCard payment system to complete a purchase, that purchase is governed by Visa and MasterCard's consumer-friendly rules. Most debit card purchases are routed through Visa or MasterCard; if you're asked when using a debit card to choose "debit" or "credit" at checkout, choosing "credit" pushes the transaction through the Visa or MasterCard system.

To contest a charge, ask the bank or company that issued your credit card for its chargeback procedures. Usually you can do it on its website — simply go to your list of purchases, select the transaction, and use a link to report a problem.

Even if you already paid your credit card bill in full, you can still contest the charge. During the time that the credit card company investigates, the questionable charge is removed from your outstanding balance and you are not required to pay it or the portion of your balance, or any interest, until the dispute is resolved. If the credit card company rules in your favor, it simply pulls the money back out of the seller's account and credits yours.

Before disputing a charge, give the offending company a reasonable chance to make things right. Chargebacks are serious problems for businesses that get hit with them: They lose the disputed amounts plus pay fees of $25 to $100, depending on the credit card company. If they get too many chargebacks, they can lose their right to accept credit cards. The process is so consumer-friendly and powerful that often just threatening to make a chargeback request will get merchants to do the right thing.

Twin Cities Consumers' Checkbook magazine and Checkbook.org is a nonprofit organization with a mission to help consumers get the best service and lowest prices. We are supported by consumers and take no money from the service providers we evaluate. You can access all of Checkbook's ratings of area service providers free of charge until Nov. 1 at checkbook.org/startribune/consumerprotections.