It sure sounds like a lot of money to me, and especially when they didn't do what you asked. For that price, they should rip out the stitching on the pinwheels and do what you asked.
Yours is not the first post I've read like this. If I ever have a quilt LA'd, unless it's someone whose work I know from this board, I'm going to sketch what I want, and have them sign it.
good luck, and don't back down. Your quilt deserves better, and so do you.