At such time as a student is no longer qualified to borrow from the fund and refunds are payable to such a student borrower by the participating institution, such refunds shall be subject to the established refund schedule of the participating institution as published in the institutional catalogue; provided, however, that any such refunds shall be made first to the fund, except in the case of loans previously canceled by insurance claims, and deposited to the credit of such student borrower. Such refunds shall not exceed the aggregate amount of all interim notes plus accrued unpaid interest and cost of insurance on the life of the student borrower.