Since this is a topic about scams, which come in dozens of different forms, and we're talking about them to help educate people, I'll take a minute to discuss the the steps you can take, if you feel moved to 'do something' beyond just hanging up or ignoring them.
Who you report it to depends on what has happened and depends on the answer to this question: Are you a victim?
Has the scam been successful? Have you sent them money (not personal information, but are you actually out of pocket money?) If yes, then contact your local police dept. Don't be ashamed. These people are GOOD at what they do. There is a reason that some folks can make a living by doing this. Don't, however, exaggerate or lie to the local PD to get a different response.
You didn't send them money, but did give them some personal information? You don't need to contact your local PD, but there is some legwork you need to do now. You need to contact the places that information may be used and let them know to keep an eye out for fraud. This will generally mean you will want to contact your bank. You will also want to contact one of the "Big Three" credit reporting agencies. They are Equifax, TransUnion and Experian. I'm told that you only need to contact one, and that one is supposed to talk to the other two. However, this is your credit rating that may be at risk, so I might 'make sure' that all three know by contacting all three. Then keep an eye on your bank account and/or credit card expenditures for oddities.
You figured out it was a scam, didn't fall for it, didn't give anyone any info, but "Just want to let us know". Your local PD doesn't need to know. They're well aware that there are scams out there. Most local PD's can't prosecute outside of their border limits, so telling them all about the very non-local phone number that called you doesn't do much. If you want to report a scam or give a phone number that called you or anything like that, you want to do it via this website:
http://www.antifraudcentre-centreant.../index-eng.htm This is the Canadian Anti-Fraud Website. It's run by the RCMP, who CAN prosecute inside and outside of Canada. They have a "Report a Scam" link right on the front page, and right near the top. If you don't have access to the internet, you can phone 1-888-495-8501. That is how scams are effectively reported for as much investigation as is possible.