Ridiculous Billing mistakes and POOR customer service

We are tired of visiting Cell C stores and calling H/O billing trying to get our upgrade done, due since November 2021. We have been Cell C clients for over 8 years on their top contract package and get shoved from pillar to post regarding our earned upgrades. Cell C employees working remotely have caused major problems with our account, showing us in arrears even though we have sent, visited and shown all our POP's for the past 8 years to be paid in full and paid before the end of every month. We are obviously not important as old clients of theirs and they are only interested in new business.