Telkom - another sinking SA ship. How do I cancel my account?

I have no idea how to cancel my Telkom landline account. The line was disconnected. I have been trying for two years to cancel and my bill just grows. I have tried to phone, tried to email, tried to get help in Telkom stores and I come up with nothing. I have been discouraging friends from buying ANY FORM OF Telkom PRODUCT. Telkom is a sinking ship but I would rather not go down with it. How can I communicate with them?