I bought an iPhone 3gs that was previously unlocked and jailbroken from a man who was selling them on Craigslist.com. I took it to Simple Mobile, and they were able to confirm that everthing was unlocked and jailbroken correctly. I put Simple Mobile sim card into my phone, and after 45 minutes, it started working completely. I set my phone down for a little bit, it ran out of battery and died. It won't turn back on even though I plug it into a computer with a USB. So confused! Please help!!!