Mrp mobile dont keep to their promises....its easy to get a call when they selling their product but its hard to terminate our contracts

Ive been trying to cancel my mrp mobile contract its was due on june its was a 12mnths contract .its not easy to get direct details and they keep on putting the amount of payment for the airtime i dont get and even use....i want it terminated if not am also closing my account with mr price i paid for 12 months if they can do a followup i never even use it at all so what is the need to carry on paying for 19months am not happy