Enter the credit card info or select Swipe Card. Optional: To save this customer's credit card, select Use this credit card in the future.After you call the card company or dispute the charge online, follow up right away with a letter disputing the charge. " Select the customer, and QuickBooks will show available credits. Solved: Here's the scenario: 1. Accidentally overpaid your credit card bill? In SumUp Invoices, go to the 'Credit Notes' tab and click 'New Credit Note'. Getting an overpayment notice may be unsettling or unclear, and we work with people to navigate the process. A refund letter format is a formal letter that expresses one's disappointment in a service or product received.