Waiting forever on a settlement letter

I was offered a settlement discount on Nedbank account by this company on the 9th of October 2025. I got a settlement letter confirming the amount I need to pay and I made the payment immediately. I've been waiting for my settlement letter, I keep calling to remind them and all they say is "we have escalated it to the relevant department" till today I am not assisted but I keep getting emails that I still need to pay before my account accumulates interest yet I have settled on the discount offer I got from them.

They have promised to send the settlement letter within 21 days after payment but till now there's no way forward on the letter.