The calls are not fraudulent. They are from a company called Strategic Communications who do the fundraising calling for many charitable organizations and advocacy groups, like the Friends of Canadian Broadcasting and the NDP. They don't leave messages because it's against the CRTCs rules for tele-fundraisers to leave messages on voicemail / answering machines, and they are obligated to call until someone tells them not to. So it's best to answer their call and politely let them know you're not interested.
This is a fraud campaign currently active in Canada using a series of VOIP numbers. The objective is to obtain your credit card number and drain your account.
If you attempt to "opt out" your number will be confirmed as live and added to a suckers list for repeated future calls.
Just got a call from this number, bu,t I didn't answer. I was surprised to read here on your site that it's a Scam Alert. I'm glad I missed it. Keep us informed. Thank you.
Had a call from this number yesterday, and another today. We do not pick up any calls from "Name Unknown", but if they have something useful to say ( and they never do) they can always leave a message.