Paid up letter requesting.

I need help regarding FNB. So I had an account with FNB that was outstanding. I then paid the account in full on the 28th July 20222. Called on the 30th to check if the money was reflecting. I was told it's not reflecting as yet. I should wait till Monday 1st of August. I did that and money was still not reflecting. I called again on 3rd of August and money has reflected into their account. Cool no problem. I request for a paid up letter and I was told that I will receive the letter within the next 4 working days. So by yesterday I should have received the letter but I haven't received it. So today I call the call center department *** the number says I have called out off business hours. How so because it Thursday and it's still early hours off the morning. So I don't understand why is it out off business hours. I sent a few emails but with no responses. So I am unhappy with this treatment because all I need is a paid up letter to state that I have completed the account.....