When I get these call from this or any other spammers I add them to my contact list. The contact is name "Do not answer". This contact has a home, work, cell, etc number saved in my phone so I can quickly look down and know to ignore it. Figure if they try often and get no pick up they will stop eventually.
added it to my phone's call block feature (rings once, hangs up) some time ago, still get called from them 2+ times a week.
What I think would be nice is if we could hire an "off duty" mob enforcer to find them and play with their knee caps... While yelling, "wrong number, wrong number. You called the WRONG number!"