Robocall. I answered the call but did not speak. After 25 seconds the computer terminated the call. They thus paid a long distance telephone toll call charge. If enough folks did this it may influence these scammers to cost to them versus any "donations" received are not worth the effort.
"They thus paid a long distance telephone toll call charge."
Sadly, I think not. I'm guessing they're doing it over IP or some other means of large-scale flat rate calling at little cost. Pick up and wait if it makes you feel better, but you're not going to put them out of business either way.
Yes, the call is either free or damn cheap. But there are two things you can do:
1. Put them on hold. That at least consumes 30 secs of their time in which they could call someone else. If enough did that...
2. Play around with them. Press 1, or whatever to talk to a "live" operator. Consume as much time as you dare. Remember, if the person is really "live" you are wasting their $$, if the person is a computer you are consuming time on their system.