those are autodiallers, they call and if you answer then it will link to a live agent or if not and there is dead space, then will dial back same time on a later date with a person at the other end or go into a recorded message (jerks!). these are from my understanding illegal to use if they have dead space. i am on the DNC list but the law surrounding it is weak, pollsters are apparently permitted to call (this needs to be changed). try this, it confuses the machines - pick up the line and then punch in at quick succession a series of numbers or hold a button down without letting up and then hang up. it seems to work. another tip is to punch in the # sign several times and hang up.
got a call from this number last night in BC. one of multiple numbers over this last week, PISSING ME OFF, pollsters, Transit Yes Coalition, pathetic waste of taxpayer $$!!!!!