I want to configure Asterisk in following way. We have 2 VoIP Plans.

1) Unlimited usa & canada
2) A-Z destinations

extensions.conf has below lines

[digitalphone-unlimited]
#include /etc/asterisk/sip-extensions/internal-extensions/*
#include /etc/asterisk/sip-extensions/external-providers/digitalphone-unlimited.conf

[digitalphone-az]
#include /etc/asterisk/sip-extensions/internal-extensions/*
#include /etc/asterisk/sip-extensions/external-providers/digitalphone-az.conf

Now i configured 2 xlite. 1 with context=digitalphone-unlimited & 2 with context=digitalphone-az when i try to call each other extension it doesnt work as both context are different. But i tried to include internal-extension/* but that didnt work. If i put same context for both account then it works but i need to 2 different context. is there any solutions for this ?

/etc/asterisk/sip-extensions/internal-extensions has following files and its content

4024645971.conf  
exten => 4024645971,1,Dial(SIP/4024645971)

4024648707.conf
exten => 4024648707,1,Dial(SIP/4024648707)

Can anybody help me in this. ?