4 requests and over a year for a settlement letter

I have been requesting a paid up letter for over a year on my personal loan account. I have requested four times and have received the following reference numbers, I don't know what to do anymore. I don't want to cause undue admin by going to the ombudsman, please can you just send me the settlement letter, so I can move on with my life. C-***6 C-***8 C-***4 C-***0 Account number ***