Kudos to you for holding out. I know A LOT of girls who'd love to get his email address from you, lol. Sadly, this type of thing is really common in NYC.
Don't let anybody (hobbyist or provider) tell you that doing this, even just once or twice, is necessary to succeed, or that it is a step in establishing yourself (I got told that...such BS!!). Business comes from treating clients well. Some of your clients WILL leave honest reviews (some might be very positive, some might not be as positive as you'd like...that happens to everybody). If you have generally good reviews, and lots of regular clients, an odd 7 (or even a 5 or 2) won't hurt your business one bit.
Another poster advised you to warn others on the local board...I wouldn't do that. He probably won't retaliate now, but if you expose him publicly, he might. He might even post a fake negative review.
There are private sites for providers only, on which you can post this guy's information. That way, other girls can avoid him. If you have PM priviliges, you can PM me for the site's URL...definitely a good place to be a member. But concerning pubic forums (like this one, or your public board), the best advice I can give you is advice that was given me: "Just keep to yourself, see your clients, and stay out of the fray."
You will be contacted by A LOT of guys like him. Some will be a bit more subtle and suave, but they will be after you, especially when you're new.