Unjailbroken iPhone help

[Reptar]

I jailbroke my iPhone but there was to many problems so I switched back to unjailbroken iPhone. Problem is when I had it jailbroken I changed the "AT&T" to "Verizon" just for kicks and giggles. Now that I went back to good ole unjailbroken it still says "Verizon" I want it to say "AT&T"! What do I do? I can't jail break again because I updated my phone

 

[LVCIFER]

Simply restore your iPhone through iTunes, and DO NOT restore from a backup, set it up as a new iPhone, and then sync all of your stuff again.