Overcharge - impossible to sort out

I renewed my daughter's phone in December on a package of R289. I am being billed R332.77. I am being charged R210.84 for the pro-rata month 23 Dec - 31 Dec. In spite of escalating this matter via the call centre (in fairness Cell C called me twice but at inconvenient times and I missed the calls). I received an SMS with my reference number, but phoning the call centre is a waste of time as they cannot transfer me to the escalation department. They also have more "verification" questions than my bank!! Management of any sort are too important to talk to customers and one cannot bypass the call centre. After-sales service is shocking, communication is shocking and being blocked from a manager who could sort this out is impossible. Massive thumbs down for Cell C.