Subject: Apology for not Crediting Payment — [Your Name] [Your Name] [Your Address] [City, State, ZIP Code] [Email Address] [Phone Number] [Date] [Recipient Name] [Recipient's Position] [Company Name] [Company Address] [City, State, ZIP Code] Dear [Recipient's Name], I hope this letter finds you well. I am writing to express my sincere apologies for the oversight on my part regarding the payment credited to your account. I fully understand the inconvenience this has caused you and I assure you that it was unintentional. First and foremost, I deeply regret any inconvenience this may have caused, and I take full responsibility for this error. As a valued customer, your satisfaction is of utmost importance to us, and I assure you that such instances are rare and do not reflect the level of service we strive to provide. To rectify this situation promptly, I have taken immediate action by informing our accounting department to credit the outstanding payment of [Amount] to your account. Rest assured, you will receive a confirmation of this transaction within [time frame]. Furthermore, I have flagged your account to ensure that such oversights do not occur again in the future. I understand that this mistake may have eroded your trust in our company, but I want to assure you that we hold ourselves accountable for our actions. We deeply value our relationship with you and your continued support means a lot to us. We truly appreciate your patience and understanding in this matter. To express our regret, we would like to offer you a [Discount/Promotion/Extra Benefit] on your next purchase or project. We firmly believe in making things right, and I hope this gesture will help restore your trust in our company and serve as a testament to our commitment to customer satisfaction. Once again, I sincerely apologize for any inconvenience caused and assure you that we have taken the necessary steps to prevent a recurrence of this situation. Please do not hesitate to contact me directly at [Your Phone Number] or [Your Email Address] if you have any further questions or concerns. Your feedback is invaluable to us, and we appreciate the opportunity to make amends. Thank you for your understanding and for giving us the chance to address this matter promptly. We value your continued support and look forward to serving you better in the future. Sincerely, [Your Name] [Your Position] [Company Name]