Xperia Z3 Compact: Software Repair Issue

[Aerostat]

I got a new xperia Z3 yesterday 27/11/17 and I tried a software repair/update straight away. However, the phone switched off during installation by itself. I received an error message on the PC companion that read "Software update failed..." so I disconnected the phone and tried to switch it back on but the phone shows an unlock icon (with the loading icon in the middle) right after the Sony Xperia start up screen. I can't get past this loading unlock icon which means start up won't complete thus I have looked up many solutions and nothing seems to work especially as the PC companion isn't detecting the phone - also physical reset button isn't working either. I need help as phone seems literally useless!

[Uliwooly]

@Aerostat

If the computer doesn't detect the phone then you have to contact your Local support to get it inspected/repaired, does the phone have any physical damage? Does the phone charge when its connected to a wall charger and computer?

[Aerostat]

There's no physical damage at all. I am not sure if it's charging but it seems to attempt to start up when connected to a wall charger.