Satisfaction Guaranteed (NOT)

I am at check out and a customer comes in with a return in a grocery bag. 4/5 books coming back in grocery bag have issues attached and this was one of those returns. Lucky for me the other cashier got the customer. On the top of the book it says 100% satisfaction guaranteed. She took the book on her trip and wasn't satisfied. She called the number on the book and they told her to take it back to the store. While she was telling us how unhelpful the book was it took all I had not to laugh. It was a long drawn out story. I believe customers tell these long stories to wear down cashiers so we'll take the return just to shut them up. (though these stories are much easier to hear when its not your customer) I walked away when the customer proceeded to call the number trying to find the representative who told her to take the book back to bookstore for a full refund. Why would anyone think they could return a used item to a store for full credit because you didn't like it? And of course the person on the phone told you to return it to the bookstore, they just wanted to get rid of you. And they probably give you a fake name.