On second thought, just let them all ring out. It will stop after a couple of months. Just for fun, pick up the phone and set it down, off hook. :^)
Have some nice background music for their pleasure.
If somebody in your world needs you, an envelope will arrive at your home.
Or blast an air horn into the phone.
I do this...some numbers have stopped calling, but others are doing a phenomenal job of picking up the slack...