Thank you for your letter detailing the poor service you received while eating at (restaurant). I understand how frustrating that situation must have been for you and apologize on behalf of the entire staff.
You server the night of your visit was a new employee and...
Dear (recipient's name),
Thank you for your letter detailing the poor service you received while eating at (restaurant). I understand how frustrating that situation must have been for you and apologize on behalf of the entire staff.
You server the night of your visit was a new employee and she hadn't received the necessary training. We were short handed, so we reluctantly let her work in the dining room before her training had been completed. I see now that was a mistake. I'm sorry you had to suffer because of our lack of help.
We hope you'll visit us again soon. Please use this (number)% off coupon on your next visit.
Sincerely,
(your name)