Caller: unprounceable/unknown had a foreign accent

Someone performing an NAB scam saying there were from the bank and asking for a transaction verification id to be handed over to them.

They knew the credit card number, my mobile number. I hung up and rang the bank's fraud section, and while talking the offender was trying to perform another transaction.

Do not hand out any transaction verification codes to any third party.

The transaction was via the US (clearing house unknown/bank did not disclose).

Subsequenly the bank has cancelled the card becasue a second fraud was attemped while I was talking to the fraud section.