keeps calling. no message left. How can I block this # ???

They have called me 5 times in the past week (3 today) and left strange voicemails where they just hang up or say "hello?" a whole bunch.  If I pick up they never say anything (just hang up), and if I call them back they don't pick up.  I filed a complaint with the CRTC

https://www.lnnte-dncl.gc.ca/plt-cmp-eng

click "continue" at the bottom

didnt awnser caled back to get no awnser or no awnsering service came up as v01131049150035 kind of disconcerning to me

Called several times in the course of a night, and asked for "the man of the house."  The caller wanted to conduct a survey and I said I wasn't interested.  She was persistent, and I asked to have my name removed from the list, which I had to repeat since she talked without listening to what I was saying.  Another call will mean a complaint.

Got the call from this phone#.  A lady from a survey company, in broken English with Phillipine accent said it was for a 1 minute survey, I consented and answered some some basic questions (any pets in the house, how long living at current address etc.).Said they want my name in case I win a prize, told them I was not interested in that.

Calls everyday!! Leaves no message. I dont want them to call again!