This number calls me repeatedly, but no one is there

This number has called me three times today, each time with nobody on the other end. I have tried calling them back to complain, nobody answered. I do not know what the purpose of this call is (scam/telemarketer/whatever), but the fact that they have callled my house so many times in one day is basically leading me to think they're calling to harass me. If they call again with silence on the other end, the number's going straight onto the block list.

Scam artists posing as IRS agents,  keep calling them back and playing with them

IRS scam artists calling from the Philippines or India

This number called me three times this morning, starting at 6AM!  I finally had it, and called back. A woman answered in muffled voice, .."Internal Revenue Service."  when I responded, "Who's This?"  she hung up.  Scammer! Each day a new number call me, except this one called 3 times in one morning.  These calls are getting out of control. Something needs to be done.