What is the ruling on a student receiving a scholarship that covers half of his tuition fees, then his guardian demands that the company, which had agreed to pay the full tuition expenses, pay him the full amount before the deduction, and the student keeps half of the amount after the deduction?

Your brother is not permitted to do that, as it involves deception and trickery. Rather, the document showing the discount must be presented to the company. The company bears the amount paid by the student, but it does not bear what was refunded to him; therefore, it requests the invoices. The matter of the discount must be explained to the company, as it has the option to pay the full amount or calculate the discount.