Dear [Company Name], I am writing to address an issue regarding a duplicate payment that was made for [product or service] on [date]. After reviewing my records, I noticed that I accidentally made the same payment twice, resulting in an overpayment of [amount]. I kindly request a refund for the duplicate transaction. To provide you with all the relevant details, I have enclosed a copy of the original receipt and the duplicate transaction receipt. Both transactions were made using [payment method]. The transaction numbers for the original payment and the duplicate payment are [transaction numbers]. Additionally, please find attached the relevant bank statements showing the double charge. Considering the error was unintentional, I would greatly appreciate your prompt attention in resolving this matter. I kindly request that you refund the duplicated payment of [amount] back to my account at your earliest convenience. It would be greatly appreciated if the refund could be credited back to the original payment method used. I have always been satisfied with the promptness of your customer service and hope that this issue will be resolved just as efficiently. Should you require any further information or documentation, please do not hesitate to contact me at [phone number] or [email address]. Thank you for your immediate attention to this matter. I trust that you will rectify the situation promptly and honor the refund for the duplicated payment. I will be eagerly awaiting your response within [timeframe] to ensure this matter is resolved expeditiously. Yours sincerely, [Your Name] [Your Contact Information]