Recently, I did a new home shop where the client demanded that I go alone, as a married guy with a young family. I had a brief exchanged with the scheduler, hoping I could be divorced, as, barring extenuating circumstances, no married guy in his right mind would buy a house without bringing his wife. I expressed concern that the salesperson would not take me seriously as somebody ready to make a purchase on the spot. Of course, the client's wishes prevailed.
On site, I did everything I could to insist that my wife "good" with the house, that she had seen it online and I had the "go-ahead" if I liked it (which, of course, I did.) The salesperson's close was, "Come back with your wife so that she can decide of she likes the kitchen, etc." I did what I could without blowing my cover, but the client did not get his desired price negotiation.
Apparently the MSC had had the same discussion with the client about the scenario and had warned the client that this was likely to happen, but the client knew what s/he wanted. So... I got paid and the MSC got to have another discussion with the client about the scenario.
It's frustrating, but not uncommon, for a client to either not truly understand the customer-interface aspect of their own business or to assign folks to create contracts with mystery shopping companies who don't. It's also common for clients not to understand what is and is not reasonable for a mystery shopper to do, especially without blowing their cover.
My favorite will always be the scenario for the one shop I have had rejected: It was a parking shop where I needed to get a photograph of all valets that helped me and the cashier. Plus, I needed to get the cashier to personally sign my receipt.
Runner up: A valet parking shop where there was free street parking right next to the valet entrance and for which the only folks who used the valet were hotel guests and mystery shoppers. The exchange went something like this..
Valet: "Good morning. Are you checking in?"
Me: "No, I'm here to visit a friend."
Valet: "Oh, you know that you can park for free right here." (indicates free parking spot on the street, 15 feet away.)
Me: "No, but thank you. This is fine. I'm here already."
Valet: "You must be our secret shopper then? The only people who pay for valet are either hotel guests and mystery shoppers."
Hard work builds character and homework is good for your soul.