Pcp Refusing to Sign Paperwork

I'm just beyond frustrated at this rate, the VA has never kept track of my paperwork properly and I am trying to file for a reasonable accommodation at work for my disabilities and my pcp refuses to sign my paperwork saying I've never been treated for it by the VA even know i have and sent proof I have they still refuse too, I'm at a lose right now, this isn't the first time I've had issues with them.

I don't know what to do because it feels like I'm hitting a brick wall and I can't keep doing what I'm doing at work, it's ruining my mental health and physical health, but yet anytime I try to message my provider the nurse under them always is the only one to reply and I never hear from my actual pcp so I don't know if what she's saying is fully true, she has said she will do something various times but never does and I have never heard from my pcp outside of appointments.

Any knowledge on this is appreciated.