Ok,I've noticed that my iPhone 3GS' battery has been draining super fast. It isn't jailbroken, it has an AT&T 3G sim card on it. I woke up today at 7am and right now at 4pm. It went from fully charged to 40 percent. If i go to the apple store and ask for a replacement, will i get a new iPhone 3gs because right now mine's in MINT condition?