Sony M4 Aqua giving continous problems

I took out a contract in April 2015 and after approximately 2 months the phone started giving all kinds of problems, battery issues, Camera taking bad pictures, Speaker did not want to work, some application were taking a lot of data etc. Vodacom could not repair the phone. Got the phone back and after a while problems started again and after 2 months it was worse and the side button stopped working, i could not unlock my phone and there were lots of other faults as well. I gave in the phone for another 3 weeks for repair and I got the phone back again and It started using a lot of data ( google play keeps using data), I tried to sort it out, but was unsuccessful. Battery started giving problems , by overheating and then shutting down because the phone is too hot. I could not go to Menlyn to give in my phone AGAIN for repairs till after a month. My phone has now been in for repairs from 7th of December and they havent come back to met yet. I have been paying for this phone every month but I wasnt able to use the phone for more than three months since I bought it. I am almost certain that it will give problems again. I want another phone or I want to urgently cancel my contract.