One of the most unfortunate realities about people and our world is the fact that while many individuals are good, honest, and are hard working, their are also some people who love ripping off you, me, and everyone else. Lots of scam artists have no remorse for scamming others. They could care less if they've harmed you and ruined your life.
I've had scam artists call me up on the phone and we're clearly trying to rip me off. And lots of others can relate.
However, many folks who know the person on the other end of the line is a scam artist will tell the scammer what they think of them.
But while I don't blame them for doing so, I don't think telling a scam artist where they can shove it makes much difference. The thing is, scam artists don't care about what you or anyone else thinks of them. If they did, they probably wouldn't be trying to rip you and everyone else off in the first place.
So if a scam artist calls you up on the phone, it's probably better just to hang up on them. You're not going to hurt their feelings by insulting them, as unfortunate as that is.