Dear Sir/Madam,

As a regular customer and a big fan of your restaurant who has recently been treated badly by one of your waiters, I am now writing this letter to make a complaint about this waiter and to demand his apology.

The waiter I would like to complain about is called Jack. This Wednesday when I was having lunch at your restaurant, he not only refused to change the wrong dish he had served me, but also refused to fetch me a cup of water by yelling at me with an excuse of being busy. Considering the way he treated me, I would like to demand his apology.

I hope you can deal with this issue as soon as possible. And wish this letter could draw your attention and urge you to provide your customers with better service.

Yours truly,

Li Ming