Some of my clients have reported people ringing from supposedly the tax office and it can be a fraud as they request tax payments from you.
Here is an excellent publication from the ATO on the various types of scammer out there. It might be worth seeing if any of these example seem similar to your situation. It includes how to verify and report a scam.
ATO Email phone and other scam type example warnings click here
Of course if you re being asked to pay money you can also check with your tax agent.