They're calling because they think there's been fraudulent activity on our CT card (in my case Mastercard). You'll want to call them back.

GTA number, unidentified caller. I didn't answer or call back.

Just got a call from that number but let the answering machine pick it up.  The girl says her name is Andrea and she's calling from the Canadian Tire Security Department (?)  I do not have a CTC card and getting info from me on the phone would be impossible, it's probably some scam.

They hung up on me.

It's Canadian Tire Security, notifying you when someone is trying to use your credit card illegally at that particular time.  It's Not a scam.  If you had answered your phone, you would have stopped that illegal transaction. Do you remember if Canadian tire had put a hold on your card and wondered why?