I would tell him that you do not want to hear form him again, at all . If he does call again or tries to contact you in any way you will have your attorney draw up papers and have them mailed to his home certified so that it will need to be signed for. I imagine he wont want his wife to get that kind of mail.

I personally do not see a need for you to go out of your way to change your number. He is the problem.