Try Privoxy, RealTunnel or Tor, as ways through firewalls that are used to block access. The Gateway Address for the Primary and Alternate can be changed along with the Port address in the set up pages of the phone system. All that is required is for the provider of the service to issue new Gateway addresses and Port numbers. This will bypass the block. However as these are known to the internet provider they can still be blocked, the local jingly computer shop may be able to help with updated settings as it looks like it will be ongoing. The Net to Phone system are very good regarding new gateway and port numbers and they work with other systems that allow you to edit them. This worked in Qatar last year when we had the same problem; the joy is that if it goes on long enough the internet grinds to a stop as they continue to restrict the access. Advice, check with the local jingly computer chaps and keep changing the access numbers, the dum Sh**ts will give up and all will return to normal. Been there and seen the video, and know how you feel.
Outhouse.