Blacklisted by Telkom due to their own Mistake!

I app**** for a credit card and it was refused due to me being blacklisted by Telkom. I went through all my accounts and could not find a single account that was not paid in time. I tried to follow up with Telkom since August 2017 and finally found out after many calls and emails that were not even acknowledged in Sept that it was a mobile Wifi device that I cancelled in 2015 already that I was still getting billed for allthough I have not received a single account for it since I cancelled the contract. I’ve spoken to more than 4 consultants who admitted that it was a mistake on Telkom’s side but further than that they refuse to help me to get my name off the credit bureau listing. Their manager, a Granny Malinga also refuses to answer my many Emails to her on 6/11, 14/11 and 16/11. The customer care consultants refuse to give me her direct contact number. I don’t know what to do I’ve tried everything but without any success. Do I just have to accept the fact that I’m blacklisted by Telkom through no fault of my own which they clearly admitted was their own fault but refuse to resolve it???? The perons I spoke to were Lyle Cable 2015 who handled the cancellation process Lounga 4/8/17 She cut me off after I asked to speak to her team leader Mpumalelo Hlatshwewe 6/11/17 refer the matter to the accounts manager Granny Malinga 6/11 and 14/11 and 16/11 who refuses to answer my Emails send to her.