Cellc disgusting services

I am with cellc for 20 years, my contract has been completed on the 3 January 2022, i told to give one month's notice to place my number on a pay as you go, without no contract, as I don't want any more debt. I gave sufficient notice, they kept on saying my account is arrears and it was not. Its normally what they do to get you on a month to month contract, which the rates are extremely high, they did that with my previous contract, which is now in debt review. I have emailed them about 20 times with proof of payment, i have over 20 reference numbers, every time i call you, they want you to email them the proof of payment, and nobody has any idea were the previous 20 emails have gone, departments don't know what is going on, there is no one at cellc that can my problem for both my numbers, i was sent a sms, saying my account is still in arrears and i will be placed on credit bureau if not paid. I called them, and guess what, they asked me to email the proof of payment again. Amazingly some of the proof of payments were sent from a cellc store. It is absolutely disgusting to know that such a big cellular network has such bad customer service and ********* ways to solve problems with such good clients.