Horrible service

A contract was taken on my name without my consent, after spending hours on the phone with their horrible call center the contract was cancelled, a few months later I am now been debited again, when I call them they have no record of the cancelation, there call center agents continuously put me on hold for extended periods with no proper feedback, this is a such a terrible company, I really want to call my bank to block anymore debits from this company however I am concerned they will blacklist me