I can understand your frustrations.
Happened to me, as well, although not until well after all the repeated questionier packages we received in the mail from Census Bureau and then the many repeated phone calls. Until finally, visits to the door. And it was how they knocked...well, it wasn't a knock..it was "boom boom boom"....pause...."boom boom boom".
I'm in the middle of cooking, and got sick of hearing someone pounding at my door, so I answer..with spatula still in hand and towel in other..clearly I'm in the middle of something.
He insists that I take "just a moment" of my time and answer some questions for the census. I tell him politely that I can't atm, I'm busy cooking. He insists that it'll ONLY take 10 minutes of my time. Again, i repeat, "I'm sorry, but I'm in the middle of cooking. It'll burn". He then responds with, "Can you perhaps turn off the stove for a moment...this will only take 10 minutes of your time".
Well, needless to say, I exploded. I told him to get lost and slammed the door in his face.
Not 20 mins later. He returns again, "boom boom boom". (I guess he calculated my cooking time would be done by then). Fortunately, I knew the knock, (or pound), and ignored him. He repeated his banging a few more times, then left a lil reminder hanging on the doorknob to contact him so the interview can be conducted over the phone...(lol..one of my pups pulled it off the doorknob and tore it up for me...lmao).
About an hour later, he returns yet again. This time hub was out front mowing lawn, (he was a sitting duck...lol). Seems the guy got his questions answered. But not by me.
Shangrala