W/r/t "he assured me that is how they conduct business"

If they printed that in their ads, they would learn quickly that most buyers won't consent to that, and use a CC. Warn them that, if not received per quote, the charge will be protested. Trust no phone conversations, keep all e-mails.
For the buyer, this is not fraud (breaking a promise does not establish fraud, which requires proof of intent prior to the promise), and not a criminal offense, so the police will listen but can't do much.

Slowly we learn that making a nice product does not guarantee honest dealing.