Contractor for large repair/remodel of my elderly parent's home left stair coverings installed incorrectly a leaky roof, bathroom exhaust fans not vented to the exterior (as specifically stated in change order, and charged for), doors not closing, etc., States they aren't coming back because "I am mean." Their liability ins. adjuster has an estimate of nearly 10k. They want out of their explicitly stated warranty. We need it fixed, and we need the warranty. Help!