Apology to customer for accounting error

Dear Thank you for your recent correspondence regarding your account number ____________. We were able to track down the error and have credited your account accordingly. A report to this effect has also been sent to our credit reporting company. As of this date, your account balance is $_____________. You are a valued customer and we apologize for any inconvenience this mix-up may have caused. If we may be of further assistance please contact this office at your convenience.