((a)) ** .—** Except as provided in subsection (b), a member of the uniformed services or other person who is paid travel and transportation allowances under subchapter I shall repay to the United States any amount of such payment that is determined to be unauthorized or in excess of the applicable authorized amount.
((b)) ** .—** The regulations prescribed under shall specify procedures for determining the circumstances under which an exception to repayment otherwise required by subsection (a) may be granted.
((c)) ** .—** An obligation to repay the United States under this section is, for all purposes, a debt owed the United States. A discharge in bankruptcy under title 11 does not discharge a person from such debt if the discharge order is entered less than five years after the date on which the debt was incurred.