Back in my Uni days I had a friend who worked as a waiter at a high end hotel in town and his reaction to a slightly picky customer who complained about his cutlery not being clean enough - and asked sarcastically for him to bring over some more dirty dishes and my friend obligingly brought over a stack of dirty plates.
And of course he was ready to quit by then I guess. (Which I thought was a good comeback but again, you need to be prepared to lose your job).
