Contract cancellation

Is it not possible for me to return the phone and cancel my contract? I’m tired of having to complain about cell c. I was inconvenienced by your *********** stuff at your branch’s more than once and I now have a bill so high because of them and to top it all off my services were disconnected while I was waiting for a call for a payment arrangement and arrangement that I was not even suppose to have but I do have because of cell c’s incompetence