Hello again after a while.
I wrote this TCL/IVR script that will call you back provided that your calling number is pre-configured in a list of ANIs. You will then receive dialtone and be able to place further unlimited calls.
The way to use it, is to assign an unused DID via a Dial Peer that has "incoming called-number" and "service callback". It is quite basic for now and I will appreciate any feedback at my email address.
Script can be acquired at ciscoscripts.com
