Ask HN: How to foil robocall scammers?

I'm so tired of being interrupted by these groups. You probably know the type of call. "The IRS/Credit Bureau/Social Security/Bank needs to speak to you immediately because blah blah blah." What can we do to stop these groups?

My colleagues and I have resorted to trying to keep them on the phone as long as possible by pretending not to know they are scammers. We ask questions that sound like we are ignorant, without giving away any details. The thought being that at least we are eating up some of their time.

Are there tools that would allow us to trace the call, or social engineering tactics we could use to determine who they are, and then take some action?