Dear Readers,
I need to setup FreePBX to be used by a small internet provider. It is supposed to be able to handle about 20-30 customers tops, someday maybe more. Anyway, the thing is:
a) how to handle billing issues like recharging, and so on. Especially important is the mechanism of controlling account status, the amount of money customers have and the mechanism of blocking or refusing to place a call in case the amount of money customers has is not enough to place it.
b) I do not know if it is possible, but it would be necessary for me to make FreePBX handle alphanumeric extensions - at the moment it refuses to do that. It makes me wonder why. I just want customers to be able to set their favorite logins on their voip-gateways, instead of their numbers.
I hope someone can help me. 
Jakub