RECEIVABLES MANAGEMENT GROUP Collection company Georgia

This company popped up on my credit report, I got a notice from my credit   Monitoring service surprised to see something there. I log in to find a Derogatory account From this company. After lookong online I found its from an account that was found not to be mine. Not only did the not contact me first to even notify me that there were collection actions trying to be taken it hurts my credit report till I can get this fixed. They state on their website they send a letter out and wait 14 days I got no such letter or of course I would have done something about it! how someone can just put false item on a credit report and get away with it makes me sick. I know I don't owe anyone money, nor did I get any notice in the mail. I will be contacting them and any other angecy I can to get this company to actually obey the law. I know my rights!