Number given is not ATO contact number. I strongly recommend you don't phone the number. But if you're curious phone from a phone box and not a mobile.

Said they were ATO Information and they kept asking for the mobile number that first received the message although I kept asking don't you want my name, address etc. He hung up on me. By the way, the ATO contact number is 132865

prerecorded number saying they are from ATO and that an audit is in order....giving us a phone number to ring to give details.
returned the phone number and came heard message to leave message.