There is a place in Sosua, in the plaza where the Orange shop is, across the street from Banko Popular, in the back in the corner, kind of a cubby-hole that unlocks phones.
I have a Samsung Rugby II phone that no one could unlock from POP to Gaspar Hernandez until my buddy took it to this guy. He was the only one that could do it and does IPhone on a regular basis too, and anything else for that matter.
Sorry I lost his card so I don't have the name of the place, but he is good and highly recommended.