You are the the manager of a restaurant that has received a letter of complaint poor service from a member of your staff

Dear Mr Smith,
I have received your letter of complaint regarding poor service from a member of the staff at my restaurant.
I would like to use this opportunity to express my sincere apology for this embarrassing and rare occurrence at my restaurant. The member of staff responsible for your inconvenience has been removed from the list of waiters and is now working in kitchen department, where contact with guests is unlikely. He has also been educated to improve his attitude. The current staffs have undergone training as well to avoid similar events in the future.
As a gesture of goodwill and as means of compensation, I would like to offer you a free meal for four people at my restaurant. You may use the enclosed voucher at any time and for any meal
I hope to welcome you again as a guest at my restaurant
Sincerely