Dear [Company Name], I am writing to bring to your attention a duplicate payment that was made in error for [Product/Service] on [Date]. I recently discovered that a second payment of [Amount] was mistakenly processed, resulting in an overpayment for the same transaction. I have included all the necessary details below for your reference: — Date of initial payment: [Date— - Invoice/Transaction number: [Number] — Amount of initial payment: [Amount— - Method of payment: [Credit Card/Check/Online Transfer] — Account/card number: [Last 4 digits] Upon realizing this mistake, I immediately contacted my bank to verify the transaction. They confirmed that the duplicate payment had been processed and advised me to reach out to you directly for a refund. I kindly request that you refund the duplicate payment of [Amount] back to my account at your earliest convenience. This matter requires urgent attention as it has caused financial inconvenience. Please find attached copies of the relevant invoices and bank statements that clearly show both payments. I trust this will aid in expediting the refund process. In addition, kindly provide written confirmation once the refund has been processed. This will serve as proof and help ensure that the appropriate funds are returned to my account in a timely manner. I would like to express my gratitude for your prompt attention to this matter. I sincerely hope for a swift resolution and a complete refund of the duplicate payment. Should you require any further information or clarification, please do not hesitate to contact me at [Phone number] or [Email address]. Thank you for your immediate attention to this matter. I look forward to hearing from you soon. Yours sincerely, [Your Name] [Your Address] [City, State, Zip Code] [Phone Number] [Email Address] Keywords: Hawaii, sample letter, refund, duplicate payment, error, overpayment, transaction, bank, urgent, inconvenience, process, attention, financial, attached, invoices, bank statements, refund process, written confirmation, gratitude, prompt attention.