Apology Letters for Unsatisfied Customers

Dear {Recipient},

It has come to my attention that you were charged twice for order number {number} due to {reason}. I
apologize for the mistake and any inconvenience this may have caused you.

Rest assured that our accounting department has already voided the second transaction. Please note that it might take {number of} business days for this change to reflect in your account.

Thank you for your kind understanding and we look forward to your continued support!

Kind regards,

{Your Name}

Dear {Recipient},

Please accept my sincere apologies for creating a false impression about {product/service} when we spoke {on the phone/via email} {last week/the other day/etc.}. I understand how the lack of information about {the price/features/etc.} could be misleading, which I assure you was not my intention.

To help you understand our {product/service} better, kindly refer to the {factsheet/link/etc.} I've attached.
Please don't hesitate to reach out to me should you have any further questions.

Warm regards,

{Your Name}

Hello