Telkom ignores my request to cancel my service

Since October 2017, I have been trying to cancel my Telkom ADSL and Home Phone number subscription. Telkom keep on ignoring my requests which I have tried to follow up numerously in their branches as well as sending emails from different email accounts to service ********** Each month I continue to receive Invoice upon Invoice for services I do not make use of. Now SMS threats are being made for late payments. I really don't know what else I can do is their cancellation department does not take calls.