Sony Xperia M4 Aqua

Hi.<br> I upgraded to a Sony Xperia M4 Aqua. The phone only worked until the 9th day.<br> It is like the battery gets extremely hot & cuts out. Pressing the power button does nothing & the screen stays blank yet the notification light blinks, pressing power & volume up button for few seconds also nothing. Even in this state I can phone the number in that phone but it does not show anything or rings or nothing. When I switch it back on after having reset it at the memory card slot it does not even show on the call history even though it was just ringing.<br> So I phoned Sony customer care who told me to try a software update. Didn't work. Then they told me to give it in, so I took it to Vodacom. They sent it back after only doing a software update (which I told them I did) & still not working. I sent it back again after telling them to even use the phone a day or two to see what it does. Once again they sent it back not having done anything & saying there is nothing wrong with it... I phoned again & I was told the same again. After getting upset they told me to take it back to Vodacom & have them send it to SSS Cellular. Back at Vodacom they said they don't work through them, they can't help me