49 CFR § 92.39
Refunds
November 18, 2020
(a) Amounts paid or deducted from the account of a current or former employee of the United States Government, pursuant to this part, for a debt which is found not owing to the United States shall be promptly refunded to the employee.
(b) Amounts which are waived shall, after proper application, be promptly returned after approval of the application.