If they are government employees it is almost impossible to fire them. DC has had quite a problem with less than efficient and/or pleasant government service employees. I can recall newspaper articles about various mayors trying to encourage more appropriate behavior in their public service people. Perhaps they have never gotten it from all too many. This is very sad for our wounded warriors.
DC government does not run Walter Reed. That's a United States government institution and I believe it's under direct military command. You'd want to go across the river to the Pentagon to complain about it.