Trying to cancel line for months! Still getting bills

Even after trying to cancel my line by sending the Cancellation Form over and over and over again, still my line is not cancelled and I still get bills to pay! I WILL NOT pay any accounts anymore. I have all the proof of me trying to cancel this line and even spoke to a consultant who 'apologiesed' on behalf of Telkom, but the apology means NOTHING as I am still being billed for a line I am not using? I have sent her mail upon mail to ask her what is going on and NO response. Nothing. Nyada. I will never ever recommend Telkom for any type of service. So sad what service has come to in this country.