Full instalments but stil arrears

I have been paying my Donna account every month, even more than the instalment. I went to Foschini Eikestad Mall to make a cash payment. The next month I noticed that I did not make the payment and that my instalment for the month of March was almost R2800. I went to Exact and asked for a statement of all the payments I have made. I noticed that the instalment of R1500 was made. I called head office and I was told that the instalment was not allocated correctly. And that it can be rectified. This morning 15/04/2021 I got a notification from ITC that there's adjustment was made on my credit report. I noticed the TFG listed that I had missed a payment, and it had an impact on my credit score. I am extremely disappointed and angry at Foschini. This is totally unacceptable. Train your ****** staff correctly. I've been with this group for several years and I am deeply disappointed. If this is how you treat your clients, I will be finishing this account and never buy from you again.