Got it. You can still do this through court, at least here in the states. Looking into it wouldn't hurt.

I'd change my number first before doing something like this. If you're careful with who you give it out to, then he shouldn't be able to find it. Short of that, you could potentially go to court and make this official since it's basically harassment. Reaching out and insulting him to get away is still contact, and may just encourage him to keep trying.