Got a call from this number asking if I had a Visa card, and when I said yes, told me I was a valued rewards customer and I had won a prize holiday to the U.S.
At this point I immediately hung up. Would be very concerned that if it was my wife she wouldn't catch on to this, and if they asked her to confirm her credit card number would give it out.

Got a call from (416) 800-2152.
Person with heavy accent identified himself as a representative from VISA asking me about the expiry dates of my Visa cards and wanted to know the 3 digit "security" number(s) on the back side of my Visa cards, kept talking about lowering the interest rates, etc. etc.
He was extremely persistent and told me that I needed a special security number in case I spotted fraudulent charges against my accounts.
I finally hung up on him.

I too  have calls coming all the time and Im on the DNC list since day one. They need to be shut down

when i picked up the phone, nobody spoke, someone hold the line for a while before it hung up. I hate this guy.

They just called same, supervisor took the phone to close the deal, blocked number but confirmed same company Fresh Air Duct cleaning.   I went to their website and confirmed their contact information.  
I have reported them to crtc as well.