Received a call at 1:20pm from this number. Automated voice recording saying my last flight was selected out of thousands of passengers for a $900 flight voucher from Westjet. Considering I haven't flown Westjet in about three years, I was skeptical so I just hanged up. I received the same call last week (they used a different number too).

This is a known phone scame, see Westjet's official press release against it: http://blog.westjet.com/westjet-warns-phone-scam/.