Bought a 100 peso cards for our Telcel pay as you go phones near Laredo and didn't put one of them on right away. It seems that cards must be added while still in the same Telcel Zone. Now we are in Zihuatanejo it is of no use to us :S So if you are in that area ie Saltillo I think and Matehuala, send me PM with your email and I will send you the number.
Zone 4 is Coahuila, Nueva Leon and Tamaulipas.
