The salary overpayment resulted because . NOTICE OF FOOD STAMP OVERPAYMENT (DEMAND LETTER) (Timely and Adequate). NOTICE.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. Try to use the Reason code and Comment to specify to which invoice the over payment belongs. We inform people about the fact and amount of the overpayment, their right to appeal, and the options to repay or, in some cases, receive waivers for the debt.