"Do you buy back books"
"Well, if we have sold a book, yes, we will generally buy it back"
"Oh good, how much for these ?"
"erm, I don't recognise having sold any of those."
"No, they didn't come from here."
"Ah, well, I won't be buying them back then"
"But you just said you would buy them......"
It went on for a while, but I really can't be bothered to type any more..