Telkom is useless

I have been dealing with Telkom for 2 months now first I needed assistance to extend my last contract payment over two months as I have had a salary cut due to corona virus. I had no help with regards to this subsequently my account was debited the full amount I have cut my losses and all I want is a letter to state my account has been paid in full and they cannot even get this right !!!!! DISGUSTING I will never use Telkom again!