Never use the word "Yes" in any phone call from an unknown source. They can cut and paste your voice into a recording and presto... you have agreed to buy something from them.

Allegedly calling from Visa & Master credit/debit card advising that there had been a $900 transaction on my card.

Couldn't advise which bank the card was issued from, or whether it was my visa or master card, of if it was my credit or debit card or advise what the last four numbers were...

After a few more questions from my end I was advised that the alleged transaction occurred in New Zealand for some sort of medical procedure for a family member I have never heard of...

I was then asked if I would like to cancelled this transaction, to which I said yes, because that is not a family member.

And after I asked several more questions the caller hung up on me...

Not sure what they are trying to achieve here....