No allocation of Payment through SS Portal

I paid an installment on the 17th Sep 2021 using Zapper, using one of their “pay now” facilities on Supersonic’s SS Portal, and my payment still does not reflect after numerous emails and confirmations that this payment was made. I notified them of this on 27 Sep and after a follow up only got a reply on 7 Oct that said this will reflect on my next statement, exactly the same comment on 11 Oct and by 26 Oct after following up again as it still wasn't reflecting was advised to make sure to reference is my account number but they would escalate it to the relevant dept. which is all good and well, however this was paid using the SS portal with my login credentials looking at my SS account including my acc number and I selected "pay now" where it automatically populates the amount due, it then takes you to several payment options including zapper, and at no point during the payment process does it show you the acc number or give you an opportunity to enter a reference number and as you are logged into your own account paying using their "convenient" facilities you take it for granted they will allocated it correctly. I have sent a follow up emails on 29 Oct, 2 Nov and 8 Nov with no response. Please can you just allocate the payment so I can move on, I have sent you multiple confirmations that this has been paid and also confirmation from Zapper that this has been paid over to you.