Telkom mistakenly and wrongfully blacklisted me

I have been mistakenly and wrongfully blacklisted by Telkom its been two years now. I have been calling the Telkom call center since more than 8months and they give me the same answer they always say they will send an email to their manager to sort it out. I cannot perform anything with my banks they all tell me that I have been blacklisted by Telkom. its been now more than 6months I'm waiting for that letter