Usually when you enter into a financial aid contract, there will be a statement about what the university can withhold pending payment of the loan; e.g., they may not issue a final transcript or a degree until the outstanding loan is paid. However, from your question it seems that they are not releasing financial aid until the tickets are paid for. My preliminary belief is that they cannot do this, unless you contracted with the university in writing, promising to pay tickets as a condition precedent.
