How can I find out why I'm not getting my total pay from Aid & Attendance?

I had been working with A&A for nine months before I received any type of payment, n we were awarded the A&A it stated i was to recieve $1,800. every first of the month. I have gotten $1,054.every month and back pay for nine months was around $3,000. the vet I care for is housebound blind wwith having only one eye, Congestive heart failure, kidney failure, hep c amongst other things. How can I find out hy im not getting my total pay for caring for this man? He cant talk to them on phone and i cant get any information.