(a) No portion of a loan may be cancelled for teaching. Head Start, volunteer or military service if the borrower's service is performed—

(1) During the same period that he or she received the loan; or

(2) Before the date the loan was disbursed to the borrower.

(b) The institution shall not refund a repayment made during a period for which the borrower qualified for a cancellation unless the borrower made the payment due to an institutional error.