Telkom`s blatant disregard to clear my name and credit score

In June 2019 I cancelled my contract with Telkom at the Telkom shop in The Glen shopping centre, Glenvista. I assumed all was fine but afterwards received a few non-payment cellphone messages from them. when I downloaded the Clearscore app on my phone last year I noticed that I had a very low score due to apparent non-payment. I contacted Telkom in January and after a lengthy process the operator said that I am totally in the right. I asked her to send me an email to confirm that I am fully paid up and I can clear my credit score. She did not send it. I again went through the process two days ago. the operator promised to send me the email of confirmation to me immediately. I did not receive it. I am at the end of my tether - I need to correct my credit score.