Denied disability increase with the VA?

My husband is 30 yrs old and he has had 2 back surgery's since 2002. He recently put in for an increase in compensation and was denied. He is now at 50% and and the doctors say that he is not going to get any better. He has degenerative disc disease, loss of feeling in lower extremities, ruptured disc, and nerve damage in back and legs. He has broke both of his legs due to not being able to feel the ground that he is stepping on. In doctors notes it states that his pain in his legs are gone and he feels better. But that is not true, he statement to the doctor was he feels better since the surgery because it did relieve some pain but not all the pain. The doctor states in the older notes that he needs multi-disc replacement but that is not possible because of the FDA not approving it. They are wanting to see him and the letter states that since the doctor has shown them that his condition is improving he may need to be knocked down from 50%. He is unable to work everyday and has a hard time motivating himself to do anything. We have 3 children and he is unable to get down in the floor and play or even play with them outside. Please if you have any information on how to deal with VA let me know. We need help.