I appealed to the University of Denver and I leveraged the appeal with a better offer from Simmons in Boston. I imagine universities have different appeal processes, but it worked well in my situation!
Yes! I emailed admissions to check what the appeal process was and they sent me a link to appeal. I wrote up a paragraph and attached an offer letter from a school that offered more money as leverage. They got back to me in a couple days with more scholarship money. Good luck!