If there is even any thought of grad school, I would not allow loans. Graduating debt free even if it feels tragic to a teenager right now is a huge gift later.
You can and should ask. Do you have a saved run of a NPC that shows a different number than what you got? Did it indicate you’d get any need based aid? If you have documentation on a change in financial situation, that may help.
But given the situation, I’d also just be prepared to walk away. Both my kids had to step away from fancier schools with more expensive bottom lines when merit didn’t come through quite as much as hoped. One kid especially had a rough go of it. We were much more pragmatic with kid #2 and then so was she once we got how the process goes. Honestly has turned out great for both, zero regrets.
Good luck!