This brief but important letter notifies a customer that he or she has overpaid you. It can serve as a very good customer relations letter.The only way to fix this is to either refund the excess payment to a gift card or allow the customer to purchase a gift card for a later use. The salary overpayment resulted because . Complaint Information. Please explain your complaint: Try to be brief, but be sure to tell WHAT happened, WHEN it happened and WHERE it happened. 1 Reports, Forms, Abbreviations, and Redelegations of Authority. 2 Definitions of Terms Used in This Handbook. Officials may use credit cards for the purchase of goods and services.