WORST SERVICE

I have a contract with CellC for almost 2 years with no issues and now all of sudden I am being over charged with my monthly installments, they gave me an open line, which I never requested and apparently I subscribed to stuff which I didn't. I complained about it and they said it has been fixed, it's now the second time they are deducting more than what they suppose to and when I call in nobody can help. Their Teamleader was suppose to call me 3 days ago which I'm still waiting for. They are not transparent on their invoice and cannot communicate to me. Atleast advise me on why my account has doubled instead of just deducting and then waiting for me to query it, only for them not to solve it. The first month I left it and now it's the second time they want to deduct so much, when I said ill not pay for the extra charges as the person who helped before said everything was sorted. She had the nerve to tell me " mam if you dont pay it its going to give you a bad record" like what the heck.