I have an iPhone 3G. I used up the whole battery to the point where it turns off automatically. I didn't think much of it, just that i'd recharge it the next morning. I woke up and turned it on. It said 0% up top on the iphone. So I just let it charge. I came back 1 hour later to see that it was still on 0%!! I don't know what to do! It has "limited" warranty remaining. Any help?