Why do you feel the need to start off a conversation with your builder so adversarially? They must have done something well enough on the first build you used them for, for you to use them on the second build. If no, and there were issues, then why did you use them for the second build?

The best approach is to talk over the issue as a team to actually solve the issue. You and your builder and other contractors are all working together to complete this project. Don't bring out the nuclear weapons at the first sign of trouble or you'll have a heart attack before the build is half over.

Kind of made me snicker as I got a similar response from LWO (but he was probably right, maybe, kind of,sort of ;). Have you taken into account all the plates and where the joists will actually sit? My finished ceiling (slab floor to Sheetrock) ended up about 8' 10" for my 9' pour. Hope it works out. My 2 cents is to point it out calmly and let them figure out a solution that suits you. Good luck

Does the contract state that the basement will be 9'.?

My guess is their premade forms possibly were not tall enough to account for the foam. Sometimes the added height is made up by stacking additional plates on top of the concrete instead of a single plate. They can stack several layers of plates, but 7" is quite a stack of plates.
Its worth calmly checking into, as its possible they have plans on how to make it 9' that you don't know about.
Avoid your lawyer...do not jump to such conclusions so quickly. However if you like throwing money away, avoid your lawyer prior to attempting to work it out with your contactor.
However fyi, had they not done it typically they would figure out a way to make it happen or eliminate the change order add, or modify it for a reduced add, but you certainly would not be entitled to additional compensation.

Additional compensation? That's nuts! You need to calm down and think rationally. Sure, you're upset, but there's not point in losing your mind completely here. If they aren't able to get you the 9', then you are only due the amount that will make you whole to the original plan. In other words, you might get the upgrade fee returned, or applied to another overage, but that's it. But, they may have a plan to get you than 9'. You just have to talk to the builder. Do not charge in with guns blazing. That is the worst possible method of communication. If you can't separate your emotions from the business conversation, perhaps someone else in the family needs to have the conversation.

23k to add 1' of concrete wall and 2" of foam...your home must have a VERY LARGE footprint. The cost of concrete and labor will vary considerably by regions though and I am just speaking for my area (Missouri).

23K is about what they charge here to increase basement ceiling heights to 9' . They have told me its for the added cost of the cement, extra foot of exterior finish materials, extra drywall, extra labour.... Just for a extra foot.

I think what some others are saying is that if it is 23 K for the extra foot, then the first 8 feet should come to 184K. I can get a very nice 2000 sq ft walkout basement with 8 ft ceilings poured for under 20K, including the floor slab. I can finish that whole basement for the tune of 20K. Even if I double these figures, I am nowhere closet to 184K, even after exterior finishes, which would be minimal on even a walkout basement.

"I think what some others are saying is that if it is 23 K for the extra foot, then the first 8 feet should come to 184K."

Except that extra height is more expensive than standard because of non-standard formwork and assuming higher back-fill, more massive walls overall (thicker, more rebar).

That said, 23k for one foot extra either means a huge, huge basement perimeter or someone is taken to the cleaners.

In my area it might mean one foot more of blasting granite...

I'd be upset. Compensating the homeowner is a lot cheaper than digging out another foot.

My entire basement (complete) using Superior Walls 10' high was less than $23K including the excavation, the stone base, all the labor, the Walls and installation of them, and the concrete floor. But it was in 2004 and is about 1300 square feet.
I am so happy with the 10' height-- but it does make for a long staircase.