How do you make sure your abusive ex will no longer contact you?
Change your phone number and cell phone, and make sure your new
number is unpublished, not just unlisted. I believe unlisted phone
numbers can sometimes still be given out by operators. Unpublished
Make sure both phones have caller ID and use it.
Get a court order to keep him away from you.
Rather than trying to convince him, set your email so that his
emails go to "junk," delete his phone calls (unless they are
threatening--record those and store recordings away from home), and
do not answer the door to him. For mail, if you have a box in the
front of your home, get a post office box to maintain your privacy.
If the lack of response from you does not work, a restraining order
may be what you need.