You will need a URI entry for each number you want to show, at least as a SUB entry.

Is this an IPEdge or a CIX? With an IPEdge I would open up Webmin and do some Wireshark traps.

I would recommend Wireshark for the CIX as well, but it is harder to setup. In that case I would contact the provider support to see if they can trap the SIP messages.

Just because the provider says that they allow spoofing of caller ID doesn't meant that it is setup correctly. They may also only allow Spoofing of caller ID on the account. Since the port is not finished then maybe the phone number is not usable yet.