Edcon customer services not helpful at all!

I pride myself in being an excellent payer! Likewise my Edcon account was always prepaid. The problems started in Dec last year, on 8 Dec I paid R200 via EFT but used my card no. as a ref no. I found out at the store that this was not reflected on my account, so I contacted Edcon on 15 Dec and asked them to allocate the money. I sent them the required proof of transaction on 7 Jan. After struggling to get hold of the person handling my query (Thuthu Buthelezi) I finally got some feedback on 9 Feb only to tell me that the money was not allocated, she accused me of not sending the proof of transaction on 7 Jan as I was claiming and she was so rude to me, I had to ask her to lower her voice as she was shouting at me. At this point (9 Feb) a late payment charge was already added to my account. When I followed up today she told me the R200 will reflect in the next statement but the late payment charge will not be adjusted. It really isn't fair to be charged the high fee when it was the Edcon employee's inefficiencies which led to the delay. I've been trying to get this sorted out for so long