I have a Motorola v3a phone I got through Alltel. Then Verizon acquired Alltel customers, and I was then with Verizon. I stopped my service with Verizon, and I now want to unlock the phone or replace the SIM card so I can use it with Tracfon. I don't have any mobile carrier with this phone right now. I want to know if this is possible, and which carrier had control over the SIM card last, Alltel or Verizon?