[snipped - um, pun intended]
Okay, I'm going to take the devil's advocate approach here. By signing up with them, you created a business relationship. While their emails may be unwanted, they're not unsolicited. Your righteous indignation is unfounded - as much as I hate spam, this is not spam, or at least it's only spam in the most liberal definition thereof.
Find a creative and positive solution. Educate, be polite, offer to set up a less amateurish mail system that would provide a way for customers to opt out of the emailings, ask your wife to learn to cut your hair. But for the love of Elvis don't act like a adolescent who's been dissed on the playground. It won't make you feel better, it won't help any other customers who don't want the emails, it won't help the business do things properly.
