How in the world shipping & receiving department c...

How in the world shipping & receiving department close at 3:30 PM,
I'm a truck driver, I drove from Birmingham Alabama to SLAC Menlo Park California, 2300 Miles loaded with a 44000 Lbs, I made it at 4 PM on Friday 03/29/2019,
The security were very polite and helpful, but, they have nothing to do simply because the shipping and receiving department is closed at 3:30 PM yes 3:30 PM,
I've been told come back on Monday 04/01/2019 at 7 AM, by the way the closest Pilot truck station is 89 Miles away.