Notwithstanding any other provision of this chapter, no adjusted premium charge shall be collected in connection with the payment in full, prior to maturity, of any mortgage insured under this chapter, if the mortgagor certifies to the Secretary that the loan was paid in full by or on behalf of a nonprofit educational institution which intends to use the property for educational purposes.

The Secretary shall refund any adjusted premium charge collected subsequent to July 1, 1962, and prior to September 2, 1964, in connection with the payment in full, prior to maturity, of any mortgage insured under this chapter, if the mortgagor under such mortgage makes the certification prescribed by subsection (a).