Apology for accounts error
[Date] [Name] [Address] Dear [Name] Thank you for your letter of [date]. We have examined our records and we can confirm that your payment of [amount] on [date] was credited to another account. This sum has now being transferred to your account [number] and will be shown on your next statement. We apologize for this error and for any inconvenience it may have caused you. If you would like to discuss this matter further please do not hesitate to contact us.
Yours Sincerely [Your Name] [Your Title]