Wrong identity - No account -No customer service, no feedback - enough to never want to deal with Telkom and its debt collectors

I was contacted in March 2017 by MBD who were acting to collect debt for Telkom. I have never had a Telkom mobile account or any other Telkom account. According to MBD I need a letter from Telkom to verify this. I have been trying since March to get a letter out of Telkom. I have spoken to Telkom's customer care line, to their call centre to everybody I could get hold of. It has been verified that I never had an account, but it always has to be handled by the Telkom credit department who has to send a letter, and than never happens. And surprise surprise - they dont talk to the public!!!! That I have been told by Telkom. The result is MBD is harassing me on a daily basis. I am fed up and I need a simple action from Telkom, whose mistake it is in the first place, to rectify an error of their making. I have all the correspondence Mrs A Forbes **********