Update. Sent my mother in law in to the store covertly back when this was going down to order 250 sq ft of the same flooring. I have it on hand.
In the meantime mil saw the carpet we are doing in the basement and decided it would be a nice Christmas gift for us to carpet the main stairway, upstairs hallway and master suite addition in the same carpet. This was never in scope with the contractor. She bought through the same store.
Last week they were here to install the lvt. I told them what was going on, and that I wanted them to come back and do the living room when they come to do the carpet. They said great, thank you, call the store and tell them.
I've been waiting a week for a quote and I found out why. Indeed they went to the builder and asked his permission. And he said no. I said why can you do that carpet upstairs for us but not the floor and they said it's because he never gave us a quote for that area.
To think I even told him I had payment ready for the other change orders. Now I will definitely not be scratching that check until every last thing is completed to my satisfaction. Asshole.