hard to tell, but you probably hurt the battery. all you can do is go to the apple store and hope that they will replace the phone if you still have warranty left. OR you can try doing a restore. that may fix the problem.
well bacically ur gonna get an extra 30%. gamestop is gonna rip you off. they will give u 20 bucks and 30 percent so in total you will get $26. so $26 is nowhere close to $59.99. sell it on ebay or craigslist. that's ur best bet. sorry buddy, but this is how gamestop makes money off used games.