Bad service

Good Day, I was owing the RCS Game account and made a full payment through VVM Debt collectors in March 2021, I have called in a couple of months requesting for a paid up letter and I was advised that I will receive it in 21 days. It’s almost 9 months now waiting for a paid up letter. I called in every week and the consultants from VVM debt collectors told me that they have escalated the matter and I should be receiving it in the next 48 hours but it hasn’t been sent to me yet. I find this very unprofessional and I’m honestly tired of calling in only to be told that they are escalating the matter to their superior as well as Game. I really need this to be sorted out as soon as possible, my credit score is very bad due to this bad record I have. Thanks