3 months without a phone

I have handed in my handset at Atterbury for repairs on the speaker that faulty. The shop consultant told me it would take 2 - 3 weeks. I have accepted the quote they send to me,but then for almost 2 months heard nothing. My husband contacted the repairs centre to find out what taking so long. According the the consultant they are awaiting payment. He was very upset because MTN didn't notify us of this. We went on 9 May 2015 to the repair centre in Midrand. According to the consultant that helped us, I have no warranty on my handset because I have replaced my handset's screen. They are false accusing me for something I have never done. We have tested the handset's speaker and still not satisfied. We left the handset with the consultant and he told us that he would help us with this issue. Up until today I have not yet heard anything from MTN. But my debit order is still going off for bad service and a no handset. Very unhappy and will not upgrade again with MTN!