Dear [Name],
I am writing to apologize for misdirecting you in the past. I understand that my actions have caused you confusion and frustration and I want to take this opportunity to express my sincere regret.
I take full responsibility for my mistake and I want to make amends. I should have been more clear and accurate in my instructions and I apologize for not doing so. I recognize that my lack of communication has caused you to feel frustrated and I apologize for that.
I understand that it can be difficult to trust someone who has made a mistake, and I want to assure you that I am committed to making sure that this does not happen again. I will be more careful in the future and will strive to provide clear and accurate instructions.
I am also willing to do whatever is necessary to make up for my misdirection. I am willing to answer any questions you may have, provide additional resources, or take any other action necessary to help you move forward.
Once again, I apologize for my mistake and I hope that you can forgive me. I am committed to doing whatever is necessary to make sure that this does not happen again and I am confident that I can regain your trust.
Sincerely,
[Your Name]