Worst network provider

Cell C is the worst network provider!!! I took out a contract with cell c wasn't happy and returned the handset back to the store because of not having any signal. Everything was approved and my contract was cancelled. Had to go through so much just to change me from contract back to prepaid and wasted so much of my time. I Have sent numerous emails and called the call centre, All they say is they will get back to me but still nothing! This is becoming on since end of February and is really frustrating as my problem have not been sorted and i have to waste my time sending emails or phoning. I have also been billed numerous times R324 for my debit order not gong off on time. How can it be R324 when others only pay R70? This is PATHETIC. I hope someone will get back to me asap after reading this.