Paid up letter

I am so disappointed with the service from cell c customer care line I have been calling from last year 2021 to date,even on the 28th January 2022 asking for a paid up letter for my contract the so called agent are soo clueless I have been sent from pillar to post.first of all its not my fault that they don't terminate a contract after it has been paid off..all I need is a paid up letter so that I can cut ties with this so called company it is by far the worst I have ever came across best you invest in training your staff about your services and products.