How to get your money back after a bad purchase
TAKE TIME TO COOL OFF
There is actually a law administered through the Federal Trade Commission that mandates a three-day "cooling off" period to cancel a sale. There are a lot of exceptions to this rule; they include sales under $25 and sales made entirely online (thus leaving out anything you bought from, say, Amazon). But it's good to know about, just in case.
COMPLAIN IN PUBLIC VIA SOCIAL MEDIA
Companies monitor the major social media outlets for any mentions of their services or products. Sometimes tweeting a short summary of your complaint, with the company's Twitter account name appended, will bring a fast response.
CONTACT YOUR LOCAL CONSUMER PROTECTION OFFICE
Most states have consumer protection offices whose job it is to help with these problems; some states have several local offices as well. You can find out what's available in your state here.
CONTACT THE BETTER BUSINESS BUREAU
The Better Business Bureau has traditionally been a major resource for consumers. Using its site, you can check businesses to see what complaints they've received in the past, and you can register complaints of your own. According to the BBB website, it submits complaints within two business days; if the business doesn't respond within two weeks, it submits the complaint again. Consumers are notified of the business' response (if any).
REGISTER A COMPLAINT WITH THE FEDERAL TRADE COMMISSION
The FTC has an online "complaint assistant" which runs you through a series of questions in order to help you file a complaint with the appropriate agency.
TRY SMALL CLAIMS COURT
If all else fails, there's always small claims court. The amounts you can sue for, vary from state to state. The do-it-yourself legal site Nolo.com has a good overview of what to consider and how to proceed. If the amount you're suing for is more than the maximum allowed by small claims (which can range from $2,500 to $25,000, depending on the state), then it may be time to consult a lawyer.