faulty handset and parts lost

I upgraded my contract in September 2014 and received a Nokia Lumia 1020. The phone started giving me a problem. It started freezing end of September and was rebooted in store . In December again it froze and went in for repairs. It came back and again in February it froze and rebooted twice that month. In April 14 it went back to repairs and came back in May. When I went to collect it I found that the sim tray was not there so I didn't take it back. An email was sent to the repairs department. No one has contacted me . I went to the shop on 4th of June and spoke to a lady who is second in charge and was promised a call the same day but no one has called. The consultant Siphoning whom I was dealing with all along said he is not paying The for the simple tray he knows nothing about. All I need is for Cell to give me a phone that works urgently or cancel this contract.