Are publicly-owned airports required to serve the community?

My local airport’s self serve station is broken with a NOTAM out about it, they have full service fuel trucks that are full of fuel. The airport, that is owned by the public and is run by the city government, closes at 7 pm but I had a flight at that time so I asked for the line techs to top off our plane at 6:30 before they left and they refused, claiming that it was too late to order fuel. There was nothing in writing claiming they had a cut off time, just an arbitrary “I don’t want to”. Is that something they can legally do? I know private businesses can refuse service to anyone but I’m curious about government employees?