while at school, my phone died. once i got home, i plugged it in and let it charge for an hour or so. when i turned it on, it said it was still on zero percent battery then immediatedly turned back off. i put it on the charger again and the LED indicator flashed blue. it did this for hours. i tried to turn it on again but this time, on the upper left hand corner it read "low battery! can't download". i don't know what to do. help!!!