No resolution after a month

I have been struggling for over a month to get my account sorted and still not done. I renewed my contract in September. In November MTN disconnected me when my previous contract would have expired as their systems dont talk to each other and they thought my contract expired even though i renewed it. Since then I have had endless issues. I was offline for 5 days with no service, reconnected but billed incorrectly which hasnt been fixed as my 1GB recurring data is not loaded, my subs fee is incorrect and there is a promo fee loaded which should be there. Since then every other week my account is barred/service suspended and i have to call to switch it back on all becoz the staff is so *********** and cant fix my account leading to endless frustrations.I have called countless times, written emails and no resolution. I am FEDUP. Where can i escalate this to to be fixed? Pls compare Oct acc with Nov and see the mess!!! I spent an hour on the phone yesterday in 2 calls to reconnect my account and i still have no service due to the overbilling on my account which is not me using more but MTN billing me incorrectly and not sorting this out.