Is the customer really always right?

I work in retail, and of course, I've had to deal with my fair share of B.S. from customers. And not too long ago, I met a woman who once worked at a bookstore. She told me that she had facial piercings at the time she worked there, and that one day, as she was serving an old woman, the old bag told her that she couldn't stand to look at her face! The old woman's behavior was clearly unacceptable and she should have been confronted by a store employee (a manager, perhaps). Being a retail employee doesn't make someone a human punching bag!