They didn't get my name. I was trying to clear it without involving my friend which was stupid!

I paid it because the catalogue did not believe that i hadn't set up the fake account and I worried I would be done for fraud as my flatmate was never registered at the address as it was temporary. There is nothing to connect her to this and it was one of MY friends she chose to do it with. My friend believes me but I don't know if that will do any good.

My flatmate, who I didn't really know took out catalogues in my friends name. I didn't find out until she moved out and I started seeing the mail. I tried to find her but can't. Problem is I tried to tell the catalogue who didn't believe it wasn't me who had done it and therefore i panicked and decided to stay quiet and pay it hoping noone would be any the wiser, well my friend contacted me today and said she's got a credit report and because I'd decided to pay it when i moved i changed address. It all points to me and I'm terrified. I don't know this flatmate well, didn't ask much about her and its bit me in the backside big time. What should i do?