iPhone asks to sign into iTunes Store with an Apple ID that doesn't exist
I'm setting up an Iphone 5 and it keeps asking to sign in to the Itunes store with an Apple ID that doesn't exist. I've checked on the Apple ID website to see if this ID is still valid which it is not. How can I get rid of this annoying pop up and continue with setting up this phone. By the way, the phone is already logged in with an Apple ID.
[Re-Titled by Moderator]