I love your attitude in that encounter, Kiz!
Yes, they must believe you have a super intelligent house if they think it can fill in a survey form, LOL.
DO you have Alexa or Google Home installed? Maybe they could speak directly to the house, haha.
So they are threatening to fine YOU are they? Next time ask them “please identify who this “you” person is It is not us, because we are not you”. The ABS Rep won’t be smart enough to pick up on this, but technically by choosing the option they gave to “you”, you kind of put your hand up and identified yourself as the person they are looking for. Not that they can do anything about it because they don’t know your proper name and If it was me I would not give them one, not even a false name. Tell them that is confidential information (and so is details of who they should come back and see.) Or do the Obi Wan Kenoboi Jedi mind trick “We are not the person you are looking for”.
They can bluff and bluster all they want but they have no legal leg to stand on unless they serve a proper written notice of direction but they can’t do that if they don’t know your name.
Besides, the relevant act only gives the Statistician the power to direct a person in writing, in an official notice of direction, to answer a specified question necessary to obtain any statistical information. This power arguably does not include the power to direct the provision of one’s name because THAT is not statistical information.
A slightly more advanced argument would be that if any Regulations did prescribe ‘name’ as a category of statistical information, they are ultra vires – beyond the power of the lawmaker to enact.
You probably will not hear from them again, but if you do – relax and have fun with it. Remember, they have no idea who the Resident is and they have no way of identifying who that person is unless someone is willing to put their hand up and volunteer to act in that capacity!