"From talking to the dealer, this is the first time this has ever happened."

Heard this B4. They know the problem, but it's costly, just keep going back till they want you to go away and they will fix it. Getting parts can take time, thats what I do and the fastest I have seen parts come from Germany is 3 days. “IF” US customs does not decide to do an intensive search on the container, that can add another 2-30 days depending on what is in the shipment.
I know it does not make you feel better, but your vehicle is under one of the best warrantees in the automotive industry, and no one wants you satisfied more than BMW.