SHOCKING Service!!!!

I requested a settlement letter from Nedbank on 13/04/2023 - made the full payment on 14/04/2023. The payment was IMMEDIATE PAYMENT, I then sent the proof of payment to the department as stated on the settlement letter. I called them the 2days later and they didn't pick up the payment so I had to wait.... I kept on calling and eventually the payment was picked up on 20/04/2023 (4days later even after the immediate payment!!!!). It's the 25/04/2023 and I called again, spoke to an Archie who was beyond rude and just told me to email the ADMIN department which I've been doing non stop without ANY FEEDBACK!!! I'm told that the paid-up letter can take an additional 7days!!!!!

Who do I need to contact to get the PAID-UP letter??? The level of service is shocking!!!