Dear [Customer's Name], I hope this letter finds you well. We apologize for any inconvenience caused by the recent duplicate order you received from our company. We highly value your satisfaction and are eager to rectify this situation promptly. Upon discovering the duplicate order, we immediately investigated the root cause to prevent any future occurrences. Our internal systems revealed a technical glitch that inadvertently caused the duplication. Rest assured, we have taken the necessary steps to resolve this issue and have implemented additional measures to prevent such incidents in the future. To address the matter at hand, we kindly request your assistance in returning the duplicate order. We have arranged a prepaid return shipping label for your convenience, enclosed within this letter. Please use this label to send back the duplicate order to our designated return address as soon as possible. Once we receive the returned items, we will process a full refund for the duplicate order, including any associated shipping charges. In the meantime, we understand the inconvenience caused by this error, and we would like to extend our apologies by offering you a [X] discount on your next purchase with us. This discount can be redeemed by entering the code [DISCOUNT CODE] at the checkout page of our website. We hope this gesture demonstrates our commitment to your satisfaction and trust. Should you have any further concerns or questions regarding the duplicate order, our customer service team will be more than happy to assist you. You can reach them via phone at [CUSTOMER SERVICE NUMBER] or via email at [CUSTOMER SERVICE EMAIL]. We highly appreciate your patience and cooperation throughout this process. Finally, we genuinely appreciate your continued support and understanding in this matter. Your satisfaction is of utmost importance to us, and we are fully committed to making this right for you. Once again, we sincerely apologize for any inconvenience caused, and thank you for your cooperation in resolving this issue. Best regards, [Your Name] [Your Position] [Company Name] [Contact Information]