Hi, i just brought an unlocked curve 8900 T-MOBILE branding NIB, Tried to create an account via web for ATT BIS. I input device PIN and IMEI and received this error:

This BlackBerry
is registered with a different service provider. Please re-register this BlackBerry and verify the URL matches the one provided by your service provider.

Do I need to formally speak to an operator before this can happen? Trying to push the service books to the phone..??? Any help

Thank you,

I already have the U-BB Data plan.