One thing I do is preach the gospel of Christ to them. They invariably ask, “what does this have to do with AluminumSiding/Insurance/AirFilters/whatever”? I say, “Well, obviously, that’s important to you. But probably not important to me. Your eternal soul is important to you, me, and God, so it’s more important than ___fillintheblank___. “ It often works, and my time is not wasted.
For those telemarketers who claim to be christian already, I offer to pray with them right there that God will give them a better job than telemarketing. They appreciate it.
I hope it works for them too.