I too have had this issue, they've been taking money out for probably well over a year now, I really should keep better track of this sort of thing. After looking around that site that Annette found, I did eventually manage to log-on, and found my credit card details on their site. So it looks like it's something I have actually joined. However, it appears to be a webcam site, and from memory, my credit card details were to be taken as identification with no charges to be made.
I've managed to cancel my account (I hope) and I'll put in as many complaints as I can find people to complain to, but I can't imagine I'll ever see my money again.