No record of arrears or payment after payment

I had an account listed on my ITC from Telkom, so I called in a few weeks ago and got the details. I then made the payment. I gave it a few weeks, called in 2 days ago. They have no trace of the payment, or the arrears, it’s like it all vanished. I’m frustrated as I paid a huge sum of money, that cannot be traced, and my ITC still has this listing, what am I to do