I used to be an orthopaedic case manager for a County.
Lawyer up, get a bulldog who will work on contingency. You can frighten them into doing the right thing, assuming it is not too late anyway. Or at least take a bite out of them. Good luck o getting much for any cash settlement, though.
Second, if you are physically capable (find out the physical criteria and get your MD to certify you can do it), they cannot fail you on that basis. If they do, it is probably in violation of the Americans With Disabilities Act; if they perceive you as handicapped, when you have objective documentation to the contrary, they are in abeyance. You may find yourself working for a boss you've already ticked off, though, and probably lose any medically indigent funding you have had to date.
Get thee to a lawyer.
PS: ah, also, in our County once you have filed suit you also lose medically indigent funding. Go TALK to a lawyer first.