can you make a att bb out of t-mobile bb

[my8320oncrack]

I had a t-mobile bb 8320 moved where t-mobile did not have service. went with att new phone. my wife was already with att and no internet on her phone. we unlocked my old 8320 called att gave them imei had internet applied to phone unlimited. there is still lots of t-mobile showing up on phone and not very responsive. is there a way to make t-mobile bb like a new att 8320 by resetting it or loading new software? Thanks for any help!!!