Working in retail a while back, this one guy called me a "kike" and "hymie" at the counter while he unsurprisingly smelled like chemicals. And I'm not even Jewish.
...because all Asian people look the same, right?
Refreshing stereotypes or cliches won't turn that customer into an open and less racist person. To come to the point that all people are equal one has to really know what ALL and EQUAL refer to.
Most customer service places have a sign that says "We have the right to refuse service to anyone" (or something close to that). I think this situation counts.