Yesterday the battery said discharging at 3% while plugged into the wall and it will not charge. At one point I got a solid green light, but now it's gone. The phone has been plugged in for 8 hours with no lights. The phone is dead and it won't respond the the wall charger or USB. I have tried holding power + volume down and power + volume down + volume up which has worked in the past, but I get no results. Please Help.