Cancellation Hell

After trying repeatedly to cancel an old Telkom Mobile 3G contract, I am at my wits end. No option I am asked to do, or available to me can help me with this cancelling the contract. None of the online tools work, as the contract is suspended, however every month they take money from me. I have been to the stores, e-mailed the cancellation alias, e-mail the online billing alias and every department who will talk to me but everyone says cant help you or we will escalate this. Considering I have been trying to do this for over 18 months now, and if i cancel my direct debit I obtain a black mark against my name - what does someone have to do to obtain a response that actually solves your query! Disgusting behaviour!