Write a brief letter that includes your name, address, account number, date and amount of the error, and a brief description of the billing error. 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. Overpayment refunds of vehicle and business tangible property taxes will be sent within 2 to 4 weeks from the date of the payment or exoneration. Call Inova customer service at 571-472-5750 for assistance with bills from any of our Inova hospitals and the following services. A. Accounts must be filed with the Commissioner of Accounts. If your refund was reduced to satisfy a Virginia Tax debt, and you have any questions or disagree with the bill, please contact Collections at 804.367.8045. Students can request a refund of the credit balance if they are not receiving Financial Aid, and the credit is due from an overpayment.