I'm pretty sure if you block the charge, that may mean reverse charge by uo, that is a sure way of banning you from ever coming back. But you can simply change the card number, get a new card like its a good idea anyway. So they will have your old and non-working number. So when billing time happens, the bill will bounce then, no money withdrawn, and you account will then close shortly, your logon will show you that there is a problem and you will not be able to log, and house will get to IDOC state shortly (-3 months? not sure).
So: If you were on a 6 month credit card pay out to them, I doubt that you will get any of the ?63 $ back. Same for the 3 months. This is why I say just get a different card, tell your credit card company that your credit card is compromised, or just ask them to just kill/cancel it and give you a new one. They will send you a new one in 2-3 days most of the time. Problem solved, no more belly-aching and you are absolved of this ordeal of trying to find the old email from umteen + 1/2 years ago.
GL to you..