What A Convenient Time For A Change Of Heart

I am designing a website for a client. This client has validated every concept, piece of art, update, and decision from scratch and has been involved in the entire creative process. After three months of work, the site is delivered. The time to pay comes.

Client: “You know, we didn’t like it so much after all. We are gonna get another one. Maybe you can make this one 50% off?”