How do I make sure my account was canceled and shut down?

I have never used this fully but had an old web developer sign me up.  I believe my CC is still attached to this and could be potentially being billed.  I need to make sure this isn't the case and cancel / delete this account.  

I checked our records for an account connected to your email address h******@selfcessful.com, but I did not find any registered account with that email. The account may have been deleted previously, or you may have the account registered with a different email. If it is the latter, then please provide us with other alternate emails we can check to see if there is an account registered with them. I will wait for your response. Regards.