look into physical disabilities,and why it's overlooked.Applying for SSI or SSDI we are denied faster than anyone.Why?

I have a rod and pins in my left leg,the rod goes from my knee to my ankle.I have 9 pins and a plate in my right ankle.My right arm is amputated above the elbow.I was born with holes in my eardrums,required 8 surgery's.Still denied 3 times for SSI and SSDI.My neighbor next door,recieves SSDI for supposed Schizophrenia.Who's totally healthy,has both legs and arms.It's evident he can work,all the jobs he does under the table.He has lived here 3 years,i have lived here 5 years.The only change i ever see in my neighbor as far as behavior,is when he is drinking.On his dmv its says HABITUAL ALCOHOLIC.Refuses to take his med's at mental clinic,but still recieves SSDI.There's so many more just like him.When i sit next door recieving no SSI or SSDI.They are only taking it from people who need it.