As to the original question…
Look at how Cornell gets to the numbers they get to. If there are no errors, then your shot at an appeal is minimal.
The ONLY person I personal know who was successful in squeezing a little bit more out of Cornell had meticulous documents and fought them on an error regarding something like rental income or some such stuff. In the end, they said the battle wasn’t even worth it for how little they got. But (and my son at an Ivy did this too), their kid took an RA job his second year. That amounted to free room and almost full board for the next 3 years. That saved a lot. That is a risky move though (to go in counting on this to happen later), as those are plum jobs and as a premed you might not have the time to do it.
What other options do you have? Can you still apply to your state non flagship or directional universities? Are you a NM finalist? While fighting the good fight with Cornell, be sure you are safely setting up another choice.