Credit Ombud/FSB Complaint: Transgression of the principles of Treating Customers Fairly

After being a loyal customer of Truworths for many many years, I paid my account late this month (first time ever) on the 6th of May. I received a statement this morning stating my account is overdue, I called Truworths immediately and advised that I made an online payment on 6 May 2019 - the agent responded very rudely I had to pay by the first and that the solution to the problem is for me to wait three business days from the 6th of May (which would be 9/10 May 2019) and call them again to hear if they have allocated my payment - how is this treating a customer fairly? Surely it shouldn't be my responsibility to follow up on allocation of payments? I then called again and spoke to a supervisor, Zaheer, to complain about the treatment I had received - he promised they would look into the matter. This afternoon I get a call from Truworths' collections department about my "overdue" account - I ask the agent to read the system notes of this morning to me. The only thing that was noted is "Customer unhappy with Collections Call" - firstly, I called THEM this morning and secondly, the supervisor made absolutely no notes about any of my grievances. I asked to speak to another supervisor and spoke to one of the Collections supervisors (I unfortunately didn't catch her name), she was the first person I dealt with today that truly seemed to understand the issue - hats off to her! Be that as it may, I will settle my full account this weekend (after my payment has hopefully been allocated) and proceed to bring this unfortunate incident to the attention of the Credit Ombud and FSB as Truworths has clearly transgressed the principles of treating a customer fairly.