HELP!! My Nokia MAIN Board was replaced!!

Got a Nokia 6015i that had the recharge power input pin snap off. Local repair shop did me a "favor", replaced the board, rather than replace the plug-in. Except that the phone was on SprintPCS, and the board came from CellularOne (which I think is also Alltel, or US Cellular). Now I have a defunct CellularOne phone, wrapped in a Sprint wrapper.
What I'd REALLY like to do is this; since I travel into Mexico quite a bit, I'd like to reprogram this thing to be my GSM travel phone, working off a pay as you go card, but...CellularOne won't help, and neither will SprintPCS in helping me with the Service Programming Code.
Is it theoretically possible to do this, and if so, how do I get someone to either unlock this thing, or cough up the SPC so I can? I know how to get into the *3001#XXXXX# set of screens, so I'm at least that astute, but the SPC is stopping the whole deal.
PLEASE HELP!!!