Have you tried to hard reset in whilst you have it plugged in? Hold Vol + and power button, let go of power when you feel it vibrate and that should bring you to the restore settings.
If it doesn't work bring it back to the store and get a replacement one, the motherboard could be faulty. In the case of being under warranty you shouldn't have to wait for your one to come back but be offered a replacement so long as they have the phone in stock.
Hope this helps.