T-mobile can be dirty. The law specifically prohibits holding numbers hostage--but they found a way to try anyway. My employer had gone under, I wanted to keep my number. No problem with my employer, they released it. The problem was I was trying to port the number to a pre-paid T-mobile number (at the time you could buy 1000 minutes for $100/year, the unused minutes rolled over. For light use it was the best deal out there.) The port kept failing, though, puzzling the employees. I finally got the truth out of someone in a call center--there was a big bill owed (duh! But I wasn't the responsible party.) I pointed out that what they were doing was illegal, the person I was talking to didn't care.

A letter to the regulators, though, a few days later I got a call from a much more friendly person who made it work like it should have. It's amazing how much better companies behave when the regulators come calling.