Review Cell Phone repairs - contract

I had a contract with MTN and my Sony Z3 Compact, the WiFi stopped working. I sent the cell phone in for repairs and 2 months later I got the phone back (repaired according to the person at the MTN liberty Mall). When I got home, I tried charging my phone and the phone is completely dead. Everything was in working condition before I sent the phone in except for the WiFi. I tried several times to call them at the Liberty Mall, but was unable to get through.

I am really annoyed and feel they should improve on their services.