5th wheel popped out of hitch

It looks to me there is new paint on the top of the hitch, in one of the pictures, but a lot of rust in another. I don't see how the the photos can be of the same hitch, if they are I don't see how it can be a new hitch. I certainly question the three washers, which I think may have caused the jaws to unlock.

I think you need to talk to the dealer, and then to a Lawyer, I think you have a good case to go against the dealer and get your truck fixed and the new hitch you were sold. I'm not a lawyer, but I work for one.