3 week long complaint, still no response

My account was debited on 18.12.2015 as per agreement, but I keep getting SMS's stating that my account will be debited on 20.12.2015... WHY???<br> <br> Upon taking up my contract, the lady (Ntombi) from the Cell C store in Sandton told me that my airtime and data would carry over to the next month if not used/depleted. However, last month i only used my phone for about 5days (Not much usage), but on 01.12.2015 my balance from November disappeared and was loaded with my monthly airtime, SMS and data amounts... WHY???<br> <br> I tried calling your call centre 3 times today (Forever useless), all I could hear was people talking in the backround and then my calls were dropped... WHAT KIND OF SERVICE ARE YOU PROVIDING???<br> <br> Resolve my query ASAP!!!!!