DEBTING BANK ACCOUNT AFTER REQUESTING FOR CANCELATION

I have been struggling to cancel my contract after it has legitimately come to an end. I have phoned Car Track so many times yet they continue to debit my account. Is this not thieving? I will not ever deal with them. This is how big companies are profiting themselves from unsuspecting clients. Their staff is so ***********. I took the contract via a phone why do I need to fill forms cancel? Delaying tactics to continue milking customers. This does not happen with Tracker.