Throw it away. The threats they imply are worthless. The Constitutional requirements for Census are pretty explicit. Enumeration does not mean total relinquishment of private information.
I had a woman in my subdivision who got a Census job and she hounded me on multiple occasions about answering questions. I always told her I was dizzy or sick or had to go for a doctor’s appointment for my hypertension. She finally left me alone
Ii asn’t as polite as you - my pseudo-census worker was somwone I know - a jerk in the village. I told him I had filled out the required forms for the 2010 census and that was it.
He argued. I told him he was recieving no answers from me. He came back 3 times, ever more persistent, even belligerent. I ordered him off my property - with instructions to not set foot on it again.
Meet him at the store often (we’re a one-store village - and he won’t speak to me. I consider that a plus. :)