ok.
you will get guarantee admission into the program if you complete the pre-finance program.
it looks like that they just want to get more money from you by making you to take one more year class with them.
i doubt that you can negotiate your way into the MSFA program. but you can give a try.
my advice: if your parents are not rich, then find a job and take a gap year. apply next year.
haha. if you really want to come to US, then apply other programs once you get your new GMAT score.
from my experience, admission committee does not reconsider its decision. so your best hope is to apply a different program.