I had a very long chat with one of the telemarketers once, trying my best to be very empathic and appealing to her humananity. I eventually hung up feeling defeated since she did an amazing job always defaulting to her agenda, and not giving in to my hippy svada in a very polite manner.

I'd be curious to hear how your approach works out. Ultimate best scenario would be to get completely removed from their lists - but I've almost given up hope on talking sense, and my provider, leaving Fire versus Fire.