Telkom ****ming people

I would like some to assist me with information on how I can lodge a complaint to telkom.

I have called call center and nothing has been resolved.

I had a 24 month contract with Telkom and I finished paying it around April and before it end a consultant called me to ask if I want it to continue and pay R149 for a 40 day and 40 night gig and I told them no I don't want it to continue they must cancel it. They did not cancel and it debited R149 month end, I reversed and cancel the debit order because I have no contract with them. Till today they still debiting and this is impacting my credit score and they handed my account to debt collectors and I have to debt collectors that I have no contract with telkom I don't understand why they claim that I owe them. I believe that their calls are recorded.