Bill me Twice for cancelling my contract and then i must wait 21 day to get my money bac****!

Cell c billed me twice for cancelling contract my because my phone was ******!!! When i woke up this morning i find they billed my bank account was bill with 11600 when i tried to call them wrt to this and cannot get through it says putting you through to collections department and no one answers the phone. I had to use a different phone to get through to customer service!!! The *********** staff send me from one person to another for more than 2 hours just to find out that they billed me twice for the cancellation of the phone!! My account is in the positive with 6500 rand, when i ask how can i get the money back, they said they need to open a case number, and it will take between 14 and 21 days for the matter to be resolved, for the matter of why my number is only allowed to call collection no one can answer me wrt to that!!! Up to this point I sit without my money and no assistance from Cell c!! Pls can anyone help me where i can report these people!!! This is terrible service and very *********** staff!!!