Caller: Visa Cyber Security

Had a person with a distinct accent call me from a mobile phone number to tell me that there were Amazon purchases being made on my Visa card, which was not my usual activity. I said ok, what card does this relate to & she said my Visa card. Ok great, which bank are you calling from? She said that she works for all banks that use Visa. I said ok great, I have several Visa cards, so which bank does this relate to? She said it relates to a Westpac card. I then say, well thats great news because I don't have a Westpac card. She immediately hung up.