INEFFICIENT STAFF DOING TRANSFERRING OF PHONE LINES

In December 2015 I sold my business New owner went to Telkom on 18 Jan 2016 to transfer telephone lines. Telkom completed forms with new owners name, address, cellphone number, email address etc, BUT FAILED TO CHANGE THE ID NUMBER TO NEW OWNER. Hence this lady has defaulted on her payments and now they are picking up unpaid account using my ID number and have handed me over to credit bureau even although I have been out of the business for nearly two years. Totally inefficient service on Telkom's behalf and now I sit with a blackmark for something I had nothing to do with. I have dealt with someone at accounts department but I need this sorted out URGENTLY to avoid having to pay penalties, interest and huge fees to some debt collector who doesn't want to know my problem. What are you going to do TELKOM???