Telkom, O Telkom; why??

During October 2017, I cancelled my ADSL and voice line. After repeated calls, finally the ADSL stopped, but the voice line carries on. I receive invoices and thought it is the last carry overs. However, I then stopped payments. I still receive invoices and as a non payer my line is still open and not cut off. At present this line is is not used, but the rental builds up. As a good citizen, I went to the Rustenburg mall, Telkom shop, and asked guidance and /or advise and they stated bluntly they could not help! I got up and walked out knowingly I deal with a useless company and people who can not help as the company employs useless people to suit the company name... Still not resolved. Maybe I should go the cell c banner way??