Ugh another iPhone question!: I trick the Apple Store support people that my iPhone is a virgin?

I’m experiencing a very annoying problem with my iPhone. It has been happening even when I was with AT&T—my iPhone thinks there is something plugged into the bottom port at all times. I get that annoying “this accessory is not made for iPhone…” message like 20 times an hour. It shuts off my audio. Anyway, my iPhone is jailbroken and unlocked for T-Mo. Is there a way I can make it seem brand new under AT&T so I can go get it exchanged at an apple store?