Ha ha! Sounds like my horse too. She was barely trained when I bought her, so all of her arena work had to be done. By me.

Here's how it went. We'd be in a lesson, trying to teach her something simple, like moving laterally away from leg. It would progress from "WTF?!?!!?" to "Um, I think this is what you want" to "Ohhhhhhhhhh! I get it now!" to "Fuck that! That's work. I'm not going to do that!"

If I know she knows what I want, I get after her, and that usually works well. Once she gets in trouble, she's much more obedient. But I also have to be mindful that she might be confused. In that case we go back to what I know she knows, and we work up from there.