Pathetic Sony Experia M4

I took out a new contract (2 September 2015) at Vodacom, Middelburg Mall, MP.<br> The contract phone - Sony Experia M4.<br> After only 2 weeks the phone overheated and screen frozen up. Vodacom had to reset it. Immediately after that, - heating problem and I have experienced speaker problems. After only 4 weeks of start of contract, it was send to service repair centre and various assessment centres. Three weeks later I got it back and was working \fine"for about 2 weeks. Still getting hot.<br> <br> Again it started to overheat and speaker problems again. Also experiencing difficulty to receive calls. When just talking on the phone"