Credit Rating RUINED!!!

Dear Telkom, Please can you assist me in updating my credit bureau account information? I have cancelled my account, the account is stated as 'closed' with TransUnion, however, when I requested a call-back from the 021 688__ number, the call agent stated that my account was not closed, the amount billed from last year July 2017 (cancellation date) had not been cleared to '0'. My credit report has been ruined, I am now rated as a bad payer. Please can you assist me in rectifying this matter with all the credit bureaus? I have reference numbers, cancellation numbers, I've requested a 'Paid Up Letter' via email to the email address provided: ********** with a new Reference Number again. I have received an automated SMS on the 20th August 2018 stating my account had been closed, surely the "debt" accrued since cancellation request should be re-set to zero? I am unable to apply for any credit, apply for vehicle finance which is rather urgent due to the Telkom Account payment profile.