A simple letter request

Once again at my wit's end over a simple request. I have been asking for a paid up letter since December 2020 and still have not received it. I fully appreciate the speedy update on my credit profile once I settlement my loan,that was amazing. All I need now is that paid up letter because without it I am unable to start bettering score.

I recently called the call centre and was given a 48 hour turnaround time, it's now well over 3 days later and still nothing.