Telkom account dispute

Zero service from Telkom and my dispute is still not sorted on Telkom's side. I cancelled a line in Jan 2019 and without any notification I was still charge up until march this year. I only found out about this negative listing on my name when I need to open my business account and now I am unable to open it because of Telkom's incompetence. I haven't received anything from them still and I still cannot get my company's business account sorted. This is unacceptable and appalling.