The job itself is an impossible one to do properly, for various reasons including contradictory guidelines and conflicting expectations. People who take on the job usually last a year or so before choosing early retirement or changing jobs.
I turned them down as politely as I could, when what I really wanted to say was "I wouldn't do that awful job if you paid me double, and I'm certainly not going to take it just to help you out, I just wouldn't put myself through the stress."
Once they realised that I wasn't playing along, their faces clouded over and they lost all interest in prolonging the conversation, trying to edge me out the door. But I wasn't having that, so I took control by asking them about themselves and how their work was going. I got them talking for a while, then I was the one who brought the meeting to a close.