A good suggestion for scam callers is, after they introduce themselves, take over the conversation and don't let them get a word in. Pretend you recognize the caller, ask them how their wife or GF is, ask about how well they recovered after a generic but believable accident like a broken arm or something, and just see how long you can keep them going. Ask them when they want to come over for a beer, it's been a while after all. And hey, we should totally go fishing again sometime, you two and maybe you'll ask (generic name) to join you too. Be sure to keep them involved, like on the fishing trip ask if you can borrow (caller's name here)'s dad's boat for it like last time. But then don't give them time to respond by shifting the conversation to the boat. Maybe it has a stain or something, maybe the engine died last time you were out. Be creative, but just keep talking
It will be so incredibly awkward for them that they'll not know what to do.
And if they try to get back to selling/scamming you, you can always ask them why they dropped out of (local school/uni here), and how they came to work in a callcenter
It's amusing once or twice, and after that you will never get sales calls again. I'm pretty sure they have a list of numbers that they avoid calling