Telkom Cancellations and Disputes Department

Telkom has made an error by adding an additional line to our account. My mother has moved her existing line which was changed to a new telkom number and which was for her own account with Telkom. Telkom went and placed the old line to our billing account. When i contacted Telkom on the 15th December 2015, the agent confirmed that i must dispute this and send an email. I have done this about 7 times already and to date i cannot get clarity nor can telkom fix the problem. Our telkom bill is standing on over R3000 for a line that is not even ours and is not even being used. To date i have not received any feedback on the dispute nor the cancellation of our existing line. I contacted the billing/accounts department and the agent is confused and cannot assist me. Pathetic service!!