Apology Letters to Client.
I failed to address your concerns promptly

Dear [Client's Name], I hope this message finds you well. I am writing to sincerely apologize for not addressing your concerns in a timely manner. I understand that your time is valuable, and I regret any inconvenience my delay may have caused. Your feedback is incredibly important to me, and I take full responsibility for not responding as swiftly as you deserve. I am committed to providing you with the highest level of service, and I recognize that I fell short in this instance. Please be assured that I am taking immediate steps to ensure that your concerns are addressed thoroughly and promptly moving forward. I value our working relationship and appreciate your patience as we resolve this matter. Thank you for your understanding. If there is anything further I can do to assist you or restore your confidence in our services, please do not hesitate to reach out. Sincerely, [Your Name] [Your Position] [Your Company] [Your Contact Information]