When the dealer fails to satisfy, you escalate up to Mazda Corporate. If Mazda Corporate fails to satisfy, you can try to escalate up within Mazda Corporate. The rep at Mazda Corp has a boss/supervisor, so you can try to get them on the phone to ask for assistance. With that said, at this current point, you've given Mazda enough chances to help you. The next step would be to lodge a complaint against Mazda on the Better Business Bureau. Following that, I would leave a review on the dealership's Google review page to advise others of the experience you had.
It blows my mind knowing that the after sales service of the auto industry in general is so poor. Sorry that you're having to go through this, but hopefully the cushion eliminates the issue and you can enjoy your new Mazda.