One must understand that those people at FA office are not stupid and they have dealed with many many "reasons". Simply saying you could not pay that much is not good enough.
Also, I believe all the discussion must take place before the enrollment of student. Once you already paid for one year, without any problem, I don't think you will get more next year unless a significant change takes place. So, if it were me, I would inform school now that we could not and would not pay the bill for the next semester. If they would not give you more FA, you would have to withdraw. Otherwise, just pay the bill and count your blessings.
We really envoy those who could afford the full price of about 6万 per year. You must have "mix it good" (混的好) and have a much higher quality of life than we poor people. So, please don't ever think those of us who get a significant need based FA as the "lucky" ones. We are not. You are.