I know that this gives you major heartburn! The fun of it is, a lot of the guys that made this mess are retiring

Were there written specs for the job?
were they followed?
what was the scope of work that was specified?

My letter to the boss would say something like:

This installation fails to adhere to industry standard practices for workmanship, fails to meet the specified design and installation requirements, and generally looks like it was installed by trunk-slamming amateurs.

The installation is unacceptable in the present state, and needs to be re-done to the specified installation requirements.

Please advise when a competent crew with competent supervision will be returning to the jobsite to properly complete the installation.