Cell C not Updating ITC

So i logged a dispute with the TransUnion because cell C has refused to update my paid up account with them. Now they are refusing to furnish the Transunion with the details that my account has been paid in full. I also checked with Experian and my account still shows an outstanding balance of R2605. This has been seriously frustrating and i feel cell c just does not give a damn. This Account was paid up in May 2017 but still nothing from Cell C, they provide me with paid up letters but are not updating. Reference number # ********** 05