Show all the adjustments and indicate the amount of the refund in the "Overpayment" box on the return and mail to the address indicated on the form. How long will it take to get a decision?Most customers are receiving responses less than two weeks after completing and submitting the DocuSign. If you were overpaid, you will receive a written notice in the mail. SECTION I - GENERAL INFORMATION - All information must be provided. Fill out the refund form (PDF) online. A supplier must submit specific documentation to support the extended repayment plan request. However, you may file a Request for a Waiver at any time. Who may have to pay back an overpayment? In this article, we'll show you how to write a refund request letter template that not only grabs attention but also persuades companies to act in your favor.