What happens when the brand-new 4K television you brought home turns out to be a bust? Or the new fitness tracker you got for your spouse doesn't work? Or, when you've been double-charged for something you're sure you only came home with one of?

If you've made these purchases on a credit card—and these days, that's a near certainty—you're in luck. Thanks to the Fair Credit Billing Act, consumers have a good deal of protection for their credit card purchases. This law allows consumers to withhold payment on poor-quality, damaged merchandise or incorrectly billed items they bought with a credit card until the matter is resolved.

Read on as we show you how to dispute a credit card charge and actually come out on the winning side.

Go Back to the Merchant

Your first move is always to go back and attempt to resolve the problem with the merchant. If you give them a chance to address your complaint they very often will, especially if you approach them with politeness and courtesy. Most large retailers have customer service policies in place that err strongly on the side of being generous, at least within a certain period of time, and under "ordinary" circumstances.

The bottom line is if you act promptly and reasonably, you're likely to get the full benefit of the doubt. If you don't have luck with the first representative you speak with, ask to talk with the manager or supervisor on duty. Be sure to keep records of each interaction, the person you spoke with as well as the date and time, so you can refer back to them if needed.

Put Your Complaint in Writing

If the merchant won't budge during your discussion, it's time to put your complaint in writing. Write a short, detailed letter outlining your particular dispute, and address it to the merchant via certified mail. Before you send it, make a few copies, so you can save one for your records and send another copy to your credit card company, as proof of your efforts to resolve this dispute.

Next, you'll draft a letter to your credit card company to officially alert it of the disputed purchase amount. The Fair Credit Billing Act mandates that you do this in writing, within 60 days after the bill with the disputed charge was sent to you. In your letter, you'll need to include your account number, the closing date of the bill on which the disputed charge appears, a description of the disputed item, and the reason you're withholding payment.

You should also enclose a copy of your complaint letter to the merchant, along with any other documentation that supports your position. This letter should also be sent via certified mail (return receipt requested). Be sure you send it to the "billing inquiries" address at your credit card company, and not the regular address for payments (since these are often two separate departments, and may well be in separate locations as well).

Maintain Your Other Payments

Even though you're disputing an item on your current bill, it's important to maintain your other obligations. If you've charged anything else on your card during this cycle, you'll need to send that payment and all interest to the regular address, otherwise, you'll incur interest and late-payment charges. What if the disputed item is the only charge on the card? Double-check with the card issuer to see if you'll be penalized in any way if you don't pay it.

At this point, you're just waiting to hear the result of your challenge. Many card companies will give the benefit of the doubt to their customers and issue a temporary credit until the dispute is resolved. This isn't required by law, however, so don't assume you will get this consideration. Meanwhile, the card issuer will get in touch with the merchant to find out their side of the story. Basically, if they end up siding with you, you will enjoy a full refund. If not, you'll have to pay for the disputed item, as well as any additional finance charges that may have accrued.

There are a few catches to the Fair Credit Billing Act. Technically, the sale must be for more than $50 and have taken place in your home state or within 100 miles of your billing address, which means orders placed on the internet (or phone) may be exempt. Withholding payment for web purchases depends on state law. However, few issuers enforce these rules on purchases, because most credit card companies are eager to hold onto your business, given the highly competitive nature of the industry these days. But, there's still always a chance that your claim could be denied on these grounds.

The Bottom Line

If you find yourself in the position of having to dispute a credit card charge, you may have more rights and advantages than you realize. The key is to act quickly and responsibly. Address the matter in a prompt and courteous fashion with the merchant in question, and if necessary, follow up with your credit card issuer. In most cases, the whole dispute can be resolved to your satisfaction within a matter of weeks.

If you fear actual fraud, call your card issuer straight away to put a stop to your card or cancel it outright.