Dear [Customer Service], I am writing to inform you that I have recently discovered a duplicate payment made to Cook Illinois Corporation. Upon reviewing my bank statement for the month of [month], I noticed that I was charged twice for the same service provided by Cook Illinois. The duplicate payment was made on [date], totaling [amount]. I have attached a copy of the bank statement highlighting the duplicate entries for your reference. The first payment was successfully processed on [date], and the second payment was mistakenly processed on [date]. I kindly request that Cook Illinois refund the duplicate payment amount of [amount] back to my account as soon as possible. I understand that mistakes can happen, but I am confident that Cook Illinois will handle this situation promptly and efficiently. Furthermore, I would appreciate it if you could confirm receipt of this letter and inform me of the steps being taken to resolve this matter. Additionally, please provide me with an estimated timeline for the refund process. I have been a loyal customer of Cook Illinois for [duration] and have always been satisfied with the exceptional service you provide. I trust that this issue will be resolved in an expedited manner to maintain our positive working relationship. Thank you for your attention to this matter. I look forward to hearing back from you soon regarding the progress of my refund. Sincerely, [Your Name] [Your Address] [City, State, ZIP] [Phone Number] [Email Address] Different types of Cook Illinois Sample Letter for Refund for Duplicate Payment: 1. Cook Illinois Sample Letter for Refund for Duplicate Payment — Overcharged: This type of letter is used when the customer has been charged a higher amount than the agreed-upon price, resulting in a duplicate payment. 2. Cook Illinois Sample Letter for Refund for Duplicate Payment — Double Billing: This type of letter is applicable when a customer has been billed twice for the same service by Cook Illinois. 3. Cook Illinois Sample Letter for Refund for Duplicate Payment — Incorrect Payment Date: This type of letter is used when a customer accidentally makes a duplicate payment to Cook Illinois on different dates but for the same service. 4. Cook Illinois Sample Letter for Refund for Duplicate Payment — Missing Payment Cancellation: This type of letter is relevant when a customer's payment cancellation request was not processed, resulting in duplicate payment. 5. Cook Illinois Sample Letter for Refund for Duplicate Payment — Payment Reversal Delay: This type of letter is useful when a duplicate payment made by the customer is not refunded within the specified period, causing a delay in the reversal process.