I think the CA extortion statute can be stretched to cover the customer's threats:
518. Extortion is the obtaining of property from another, with his
consent, or the obtaining of an official act of a public officer,
induced by a wrongful use of force or fear, or under color of
official right.
519. Fear, such as will constitute extortion, may be induced by a
threat, either:
1. To do an unlawful injury to the person or property of the
individual threatened or of a third person; or,
2. To accuse the individual threatened, or any relative of his, or
member of his family, of any crime; or,
3. To expose, or to impute to him or them any deformity, disgrace
or crime; or,
4. To expose any secret affecting him or them.
http://www.leginfo.ca.gov/cgi-bin/di...0&file=518-527
Good luck getting the authorities involved at that level.