It's good to rant when frustrated!

I think maybe the key word here is permanently? Some are on disability on a temporary basis and expect to return to work. It sounds like they just need to have documentation on file that establishes or verifies that your doctor doesn't expect you to be able to return to work. They need to document all supporting information for their decision. This will protect you from someone coming along later and questioning that decision, so even though it is a pain now it will be a good thing for you in the long run!