companies selling apps to identify who is calling, or selling apps to block unwanted calls, are almost certainly the ones doing this, relying on people’s curiosity, or anger. Who else would have a vested interest in this? Don’t reward them by buying the apps, just ignore the phone calls from anyone you don’t know.
Not everyone has the time to do this, but my way of dealing with it is to listen all the way through, punch the buttons until I get a real person on the line, then lay the phone down and let them talk until they realize they are talking to a counter top. It wastes their time and since someone did actually answer the phone they don’t pass the number on to some unknown list. It does not stop the calls, but it does keep the number of calls down to the same callers, and i’m getting only 2 or 3 a day.