"God Damn it, Rod! I said if you called again I'd tell the cops what you did! Oh wait, who is this?"
Pretend to be an answer phone:
"Hello, I'm afraid I can't get to the phone at the moment, if you could just leave a message after the tone I'll get right back to you... now fuck how do I get this to stop recording, Stupid mother fucking shit just work damn it, HOOO-LEE FUCK now I've got to start again, fucking ass wipe shit FUUUUUUUUUUUU- *BEEEP*"
Rick roll telemarketers till they cry
"I can't keep up the lies any more, look, I know they'll kill me but I have to tell you. You haven't been selling anything to anyone, your company, they've just been connecting you to actors. It's all just a huge sick experiment to see if people will follow orders, see how unscrupulous people will be selling worthless and dangerous crap to vulnerable people!
It gets worse, eventually they'll have you selling faulty medical equipment to disabled people, they are trying to select the most heartless and obedient. Run! RUN while you still can! Oh god, he's here!"
(fake voice) "Get away from that phone"
"NO! you can't stop the truth!"
*scuffle*
(fake voice) "Ahem, don't worry about that guy, that's just a prank call, now you just tell your handler exactly what happened here and... uh... don't tell anyone else about this conversation. There definitely ain't no conspiracy to test authority compliance, just do your job and follow procedure. What's your employee code by the way?"