Just answer, "Hello, States Attorney Office, Online fraud division, How can I help you?"
Or, ask them to call you back on your other phone and give them the number to the fraud division.
When I was shopping for a car one time I clicked on one dealerships "Live Help" chat and got the "can we get your name and phone number in case we are disconnected" from a person that didn't know anything about the cars or dealership. So I checked one of my other browser tabs I had opened and gave them the name and number of a salesman at a competing dealership.
I wish I could have heard the call
"I'm returning your call about the RAV4"
"Yeah, are you still interested in it"
"Me? No, I thought you were interested in it"
"Wait, what?"
It would be funny to just start walking around the house and trying to sell them stuff you don't need anymore. "I've got a pot holder, it is fairly worn but still works, what seems fair? $2? You want it for $2? Shipping and handling would be extra, of course"
Another good one "Thank you for calling KQCA, you are caller 37, keep trying" and hang up.
I have heard advice to not even say anything though because they can deepfake your voice with a short clip and I knew a guy that spent months fighting to get his bank to return money to him that they had transferred because they said he called and requested it....