Telkom listing on Transunion

I need help, I paid up my Telkom mobile account on the 22 July 2016. R675 as advised by their employee. When I call Telkom they advise that I do not owe them, but on Transunion it states that I owe them R675, I do not know how to deal with this anymore i have called emailed Telkom the proof of payment but they are just not bothered.