Spam calls

We've been getting a lot of calls from a certain number, and a quick Google shows it's a "collection agency" that's been harassing people about accounts they've never had. So, basically, scammers trying to get your info. I've been just letting the answering machine get it (no messages) but wonder if there's a better way...

[Poll #1413012]

I won't do anything to hurt the person (like a fog horn in the ear) but scammers - even lowly phone people - should be punished.