When it is plugged into the computer it shows the animated battery charging, but it never gets full. When we unplug it from the computer and try to turn it on it shows low battery and shuts off, or it just simply won't turn on at all. When we plug it in to the was with it's cord, it says "Battery full". We unplug it from the wall and it won't turn on at all. Help please! This was a gift for my nephew and although we have all the original packaging we can't find the receipt. Thanks very much, Amy