One of my friends is receiving unwanted email from a big motion picture studio, and can't make it stop.
Continuing to send email to a recipient after they have unsubscribed is lame, and illegal. It is a violation of US Federal Law, just as sending emails without an unsubscribe option would be. But, the fact of the matter is, that for the Average Joe Recipient of an email, there isn't a lot of recourse; no easy option to rain down a hell fire of pain on somebody who won't stop filling your inbox with their unwanted email. And no legal standing to sue -- only ISPs, the FTC or states attorneys general can take action under CAN-SPAM.
So, you don't really have a big stick to wield, Mr. Average Joe Recipient. But, that doesn't mean it's hopeless. Here's what I would do if I were in your shoes.