Wrong Sim card activation!

[hobodude666]

I purchased a new 3gs and i accidentally switched sim cards with my dad and now my phone on itunes shows my iphone 3gs activated with my dads number. how do i fix this?

[blkcadi]

Put in your sim card and sync.

[hobodude666]

i tried that already still on itunes it shows my 3gs as my dads number... do i have to bring it back to att for reactivation im afraid theyll charge me a fee again

[i.Annie]

Restore?