Samsung :: Carrier Locked Phone For Non-payment?

I am attempting to help a friend and also satisfy my curiosity. She has a Samsung "Rant" through carrier Sprint. She said that after her phone was turned off for non-payment, she can no longer use the phone. She claims she has been remotely locked out, as if you set a security lock code and forgot it, that kind of locked out. She swears the company locked her out to keep her from getting at her contacts. Is this even possible? I googled and the only thing I can find is blacklisting lock outs using the ESN, which I already realize. But to actually lock the hardware remotely, is another thing. I know they can remotely unlock. What is her best option to recover those important numbers, and do all carriers actively do this sort of thing (if it's even true?)