Poor Service

My Blackberry Z3 is giving problems charging , Last week Thursday I took it in to be sent for Repairs for the second time this year within a two month gap, The Consultant at Cell C insisted I cannot change the phone for another make as I have already signed the contract, I have been forced to go out and buy a another Cell phone for me , with the new cellphone I've bought im forced to use the number the accompanied the phone as it's with MTN. Never in my life have I received Service so pathetic and it looks like Cell C does not worry about the Customer at all. I have now been inconvenienced for the second time this year because of Cell C and they are not willing to change my contract or phone. I would not advise my worst enemy to take out a contract with Cell C.