While I wouldnt tolerate being treated the way that the trainer treated you, maybe giving her one more time for "free" would be a good thing. If you want to take lessons from her after and things are good, then it could be a great thing. If not , then you can tell her you no longer want to take lessons. Her teaching just doesn't mesh well with your goals .
Horses and children, I often think, have a lot of the good sense there is in the world.
Josephine Demott Robinson Feed, muck, groom, ride. Repeat daily!