[42pilot]

I agree - call BMW NA and lodge a complaint.

Then, I would write them a letter explaining your position and why you feel you should get your money back (it's the principle of the thing). Keep the letter professional and with facts. Ask them to refund the money within 14 days or you will forward the letter to BMW NA, publish the letter on all BMW forums that you frequent (name them for emphasis), and send a copy to the owner of the dealership (personally).

I did this with a year-long disputed hospital bill and the hospital made it disappear in 48 hours.