Unauthorize payment

I had an account with Foschini and I paid the account in Full on the 9th July 2020. The last payment I made was R2950 and I made 2 separate payments, a R2000 payment and then a R950 payment, both payments were made on the same day. To my surprise when I checked my credit report it showed that Foschini shows that I am owing however the receipt that I received after making payment the balance in the receipt was R0.

I called Foschini this morning 27th June 2023 and they gave me a number to call because they said my account was handed over. I called the company IDC and they informed me that I owe R501 and the lady I spoke with said Foschini should have given me a paid up letter however this lady said I should pay this R501 amount. How can I pay when I received a receipt saying I have a R0 balance. Can my name please be cleared as I have a receipt that is saying R0 balance. Foschini please sort this out because I paid my account in full, why should I be paying IDC when I never bought anything from them.