Just got a call too. Same thing, about a 'recent survey' I took. It sounded like it was getting cut off, so I said, what survey, and there was a pause before the guy repeated the same thing, then hung up.
As what you said above, I got the call, the guy seems didn't care what you talking about, he just said what he want to say, when I ask s.th to him, the conversation is over.