Fun story: My work has a dedicated voice mail line that rickrolls people. We frequently transfer telemarketers to it.
This one guy called a few weeks ago. He wanted to talk to someone that frequently gets calls when he shouldn't. Something about "wanting to confirm the event" with him. I talked to my co-worker, and he said he didn't have any events planned. Another coworker overheard and told me to not pick it back up, and that he was going to have some fun with it. So he starts asking him a bunch of the same questions I did (who are you, what do you want?), and he was able to get out of him that he wanted to do a sales meeting over breakfast and a movie. So my coworker told him that he'd have the guy call him back, and hung up. He never got a callback number or anything. We all had a great laugh about it.
That should have been the end of it, but the guy called back almost as soon as it would have taken him to hit the redial button. My coworker picks up immediately and said "I'm so sorry, I meant to hit the transfer button. Let me transfer you to Mr. Rick Astley." This guy also manages the phone system, so he was able to see how long the guy stayed connected. The telemarketer listened to the WHOLE song before the line auto-hung up on him. So about 3 minutes later, he rings again. This time, a new guy picks up. Starts asking him all the same questions (Who are you, what do you want?). So instead of messing around more, he got a callback number from him. After hanging up the phone he called the number and found it went to a voice mail box. We were kinda surprised he didn't answer right away, but we decided to fuck around with him just a bit more. We called the number, and right as the voicemail was to start recording, we transferred it back to the rickroll line. At some point the guy is going to check his mail and get rickrolled again.