Cell C Incompetence with account statements but hands you over

I have been a Cell C customer since January of 2018, and had to firstly cancel my debit order due to their incompetence as they cannot deduct your debit order on your instructed dates. I have since been paying manually every month.

In January of 2023, I received a statement saying I owe R315.60, which I paid in full in January. Come February, to my surprise my opening balance is R461??? I have been battling since February to get this account sorted to no avail. My router, where the amount is only R157.84 per month is never working, phoning them does not help. I have spent hours on the phone trying to sort out this account. Fighting does not help, they chuck the phone down in your ear, I am so frustrated by them it is not even funny. They are always "escalating the matter", no one ever calls me back, but I receive daily notifications from them stating they want to collect the money. I have asked nicely, fought, literally swore at these people's incompetence, but my account just does not get sorted. Going into a store does not help, as they refer you to phone customer care, which does not do s##t, to sort out my account. I am sick and tired of incompetence dealing with them when they cannot even sort out my account. In February I was told they went over to a new system and that is the problem. We are now in September of 2023. My router never works, although I pay every month, whilst being handed over to collections every month. What else must I do to get this account sorted. These people are completely useless