In my town, the conductor's employee number is written up at the front of the vehicle. So I'd copy the number making sure he sees me do it. Not a word, not a threat. Just that.
If he continues after that, I'd report them to customer complaints.
At stores, what I do is just ask politely for the person's full name - first and last. They get the message that I'm gathering info to go complain, and stop it immediately. I don't need to argue, fight, explain how I'm feeling, plead for respect, nothing at all. A simple "Can I have your full name, please?", clean, polite question that stops the abuse.
_________________
So-called white lies are like fake jewelry. Adorn yourself with them if you must, but expect to look cheap to a connoisseur.