What do you do when a client

…aproves all the previews you send him about the web design project you are developing for his business, and he loves them and he says change this change that, oh it is perfect!, I like it, please move this color, move that, change this font, he agrees in everything for 4 weeks and is very happy and when the structure and project is done he suddenly says: I DON´T LIKE IT, is too inferior of what I asked for at the beggining (?!?!) And when in the contract says:

“The changes in the design or structure of the page once finalized the project will be decided by the two parts, previous economic proposal.”

Then what do you do?? What do we have to do next?

I know the answer but I need to hear it from someone else to make me feel better about this ****ty client…