PAID UP LETTER: Poor customer service

After struggling to pay off my FNB Personal loan account, I finally managed to pay it off on the 20th July and with excitement I tried to get hold of FNB telephonically to obtain a Paid Up letter but what I am getting is poor service.

When calling the call center, I am sent from pillar to post, I have also sent an email with no response, I also visited the branch today only to be told that I need to call center of which they are not assisting.

Before settling my account I had a balance of R15 003 and when I check on the app, the settlement amount was R15 065, 35, I then paid R15 100. Today when I check I have a balance of R313 which is the credit insurance. How am I charged credit insurance on R0 balance and what credit am I paying for as I have paid my account.

Can you kindly send my paid up letter and close off my account, PLEASE.