It was a pretty short sighted move by the barber shop owner to refuse the hair cut to this woman.
Yes, you are a men's barber shop and she has lady parts, but you've gotta pick your battles and I'm not sure this was the right hill to die on.
Or in the words of the dude: (NSFW language)
She had money, and wanted a service you provide, she just happened to be outside of your typical demographic.