Unlock i337M Telcel
 

Greetings to everyone in this community ... I raise them a little I've done with this team ... is a Telcel Mexico Samsung i337M
I've released with Z3x and the procedure was simple, the team had version 4.3 and lower than 4.2.2, then did unlock with box
and as that version gave me trouble I went back to put the 4.3 and the computer works perfectly but I want unlocked for Movistar
use with Nextel, someone with experience who can help me on this issue?? Nextel put the sim and try to make a call
tells me that is not registered on the network.
Thank you very much. Greetings and again.