What type of lawyer do I need to sue Social Security for wrongfully turning off my son''s check? Also what steps do I need to take to pursue this?

Social Security said he does not qualify when he is an autistic child who can not talk, clean himself, or do anything else for himself on his own. There are people who fake mentally ill and receive SSI and my child who can not take care of himself at all does not qualify. (the legal topic is inncorrect because it would not stroll down)