Subject: Request for Prompt Refund Regarding Duplicate Payment [Your Name] [Your Address] [City, State, ZIP Code] [Email Address] [Phone Number] [Date] [Recipient's Name] [Recipient's Position] [Company's Name] [Company's Address] [City, State, ZIP Code] Dear [Recipient's Name], I hope this letter finds you in good health. I am writing to bring to your attention an inadvertent duplicate payment made to [Company's Name] on [Payment Date]. I kindly request your prompt attention and approval for a refund of the duplicate payment amount. Upon reviewing my records, I discovered that I inadvertently made a duplicate payment of [Amount] to [Company's Name] for [Invoice Number/Description]. The initial payment of [Amount] was settled on [Initial Payment Date], and the duplicate payment of [Amount] was mistakenly processed on [Duplicate Payment Date]. I apologize for any confusion caused due to this unintentional error. To ensure smooth and seamless business transactions, I kindly request that you investigate this matter promptly and process the refund of [Amount] to the original payment method used. Please note that the duplicate payment amount can be easily verified by cross-checking your records against mine. I have enclosed copies of my payment receipts, including the duplicate payment receipt, as supporting documentation. I sincerely hope that such an error can be rectified promptly and efficiently. My experience as a [long-term/customer name] with [Company's Name] has always been excellent, and I believe this matter will be handled with the same level of professionalism and attentiveness. Kindly confirm the receipt of this letter as soon as possible, and provide an estimated timeline for processing the refund. Should you require any additional information or further clarification, please do not hesitate to contact me at [Your Phone Number] or via email at [Your Email Address]. Thank you for your immediate attention to this matter. I trust that your team will handle this situation diligently, ensuring a swift resolution and the return of the duplicate payment amount. I value the ongoing business relationship between our companies and look forward to maintaining it in the future. Yours sincerely, [Your Name]