FNB - refusing to provide me with a settlement letter

I have been trying for the last 3 days to get settlement letters on my credit accounts in order to settle my debt. After numerous phone calls and emails and secure chats I have received my personal loan and credit card settlement letters. After days of waiting I have now been told (on an email showing my settlement amount) that you do not issue settlement letters for revolving credit loans as the amount is only valid for a day. I am simply asking that the information contained in the email (the settlement amount) be put onto a letterhead stipulating it is only valid for one day which is what I have received for both of my other accounts. I have even gone into a branch and was directed to use online banking or call the call centre. I can't believe that such a large institution cannot fulfill a simple request.