The delays and lies

I got a phone from Mtn and within three months it just started malfunctioning. I understand that factory faults happen. I took it in as it still qualifies for a warranty. They told me to wait for two weeks. End of second week I went in and they told me my find my iPhone is on so they couldn't do anything. Why wait for two weeks to tell me this? Okay, called this number *** and they told me to disable find my iPhone and call back quickly. I did that and they told me my request should be processed in the next 24 hours. It has been 3 days and they keep telling me to call the following day. I cannot survive another week without a phone. I am really considering any options I might have to cancel this contract. If this doesn't get sorted Mtn has lost many potential customers including me.