Don’t fall for the snake oil salesmen pushing credit repair scams on the internet. Save you time and money buy purchasing Nolo Press’s how-to guide on credit reporting and repair. Follow the steps it outlines and, if errors stay on your credit report, get an attorney to sue. (Once you do the leg work, many attorneys will take your case on a contingency fee basis.)
Question whether they are scams? Read this helpful information from the Federal Trade Commission. And keep in mind they will not be able to do anything you cannot do for yourself for the costs of the books (less than $50) and the costs of stamps.