Default Photon won't turn on

I was running today while running my music and the RunKeeper app. After about 20 minutes, the whole phone died, although it was charged. Ever since then, it won't do anything unless plugged in to the wall charger, and even then, I have to hold the cord in, and it only stays on for about a minute before dying. It says it is 100% charged. The phone is only about 35 days old. Any suggestions are greatly appreciated. I'm at my wit's end!