I've been called by them twice. The first time, I answered "4192 nonsecure, identify and authenticate". A confused man asked me "Is this Ray?" I repeat my one line, they hit some buttons on their keypad because I hear the tones. We go along like that for 5 minutes before he hangs up. The Indian callers usually give up in 15 seconds, so that person....was really down there.
The second time, I did something far worse. I had a woman call me, so I turned it into a little naughty time with the phone "What are you wearing?" "Oh, that sounds hot, say it again for me." I was interested to see how far she would take it, and she took it pretty far. So glad it was on her dime.
Called several times, did not leave message, just on long enough to set the recorder to start. Calls twice a day, once around 9:00 am and then again at 2:30.