Can't cancell an account

I do not even know where to start. I tried cancelling my Telkom contract for 6 months now, I do not have a landline or router, the service was cancelled before they could even put in the landline, they are deducting money montly from my account.

Cancelled the account in November previous year, January still debiting my account. Then I phone in January says the service was never cancelled.

Send numerous emails, logged disputes, sent cancellation forms, went into the store and still no stopping of the account or debit order.