Request for a paid up letter

I have been engaging with cell to sent me a paid up letter since last week(21 July 2020). They have promised me that their consultant will call me. I have made the payment last year but till today they have not cleared my name. Now when I request a paid up letter they have an issue and cannot sent me the letter before their consultant calls me back. I've been waiting for the call since then. Call them again on Wednesday (29 July 2020) again they promised to give me a call. Bt no one has called me. What do we have to do in order to get a paid up letter?