Asterisk is fail?

I installed a server for call center. My version asterisk: 1.4.18: Asterisk 1.4.18 built by root @ localhost.localdomain on a i686 running Linux on 2009-10-10 20:45:07 UTC. with my configuration:

exten => 190017XX,1,Answer
exten => 190017XX,n,Background(custom/19001799/sport/introduction)
exten => 190017XX,n,WaitExten(30)

extem => 1,1,Background(custom/19001799/sport/introduction1)
exten => 1,n,Hangup
exten => 2,1,Background(custom/19001799/sport/introduction2)
exten => 2,n,Hangup
exten => *,1,Background(custom/19001799/sport/introduction3)
exten => *,n,Hangup

And in my countruy, there are 2 telecom company: VN, MO. I don’t understand why I use sim of VN,I call 190017xx, I still hear sound of introduction file, and I press 2 I will hear sound of introduction2, or I press 1 I hear sound of introduction1. But I use sim of MO, I call 190017XX, I still hear sound of introduction file, but I press 1 or press 2, but I can not hear introduction1 file or introduction2 file but I still hear sound of introduction file when I press 1 or press 2. And, I showed log, but I see that my asterisk server didn’t received press 1 or press 2.

Therefor, I think this error is caused by server when I configure, but I don’t know where I have to configure? Who know this problem! Please help me

Thanks in advance! Sorry for my English