What is the ruling of Islamic law on using a bank savings account to pay expensive university installments?

A committed Muslim is not permitted to rely on something that displeases Allah, such as usury (riba). He must, instead, place his trust in Allah concerning his studies and seek sustenance from Him. As for past usurious gains, if he can donate the surplus to the poor, that is better. Otherwise, he must seek Allah's forgiveness and repent to Him.