bad service

I went to mtn in waterval on the 29th August after I was ****** at gun point and my phone was ******.i was given a new phone iphone 5s.after two days the phone stopped working and I returned the phone I was told to come after a week as I don't qualify to get another phone.i went after a week to mtn and was told that my claim now is still pending with the insurance dept and was given this reference number ***3.its almost three weeks and when I go to mtn am not getting any help even though never missed a payment for my number.***