Bad listing on credit report

I recently pulled a credit report only to find that Telkom has listed me for non-payment of my account back in 2015 / 2016.

This account was cancelled in November 2015, but only processed by Telkom in April 2016. I owed an amount of R930.46 which I paid, but I am now unable to find proof of payment. I called Telkom again today to find out how I can make payment to just get this off my name and finalized, but no one is able to tell me how.

Either tell me how to pay this or remove the inaccurate credit report.