I called back number (02) 4032 8512 spoke to a guy but did not say for what company.
Anonymous on (02) 8904 5375
Left a message in Mandarin.
Anonymous on 0452 136 497
Left a blank voice message with clear background noise indicating an office.
Anonymous on +61 85229594480
They rang no one at the other end but in the background was the sound of a call center
I Called Back on (02) 6189 1265
I rang back the number (02) 6189 1265, spoke with someone who hung up right away
Anonymous on (02) 6559 1881
Said it was final warning from the tax office 🤣