I contacted Amazon.de and after I explained the situation they offered me a replacement. When I explained that this would not solve the problem since the item image on the website is wrong, they gave me a full refund. However, it is clear to me that they still do not understand the problem judging by this excerpt from their final email:
"I have now initiated a refund for the article "Pacific Rim 3D Steelbook (exklusiv bei Amazon.de) (3D Blu-ray)".
I have cancelled the replacement order.
We suppose that there was a packing mistake in stock when the shipment to your order was prepared.
With the replacement order we intended to send you the correct article.
I hope that your future orders will be more satisfying."
I hate to do this sort of thing since it is really the fault of Warner Brothers and not Amazon, and it is an expensive concession on Amazon's part. However, they need to learn that this kind of thing is not appropriate when people are buying relatively expensive items that they otherwise would not buy. While this is a financial victory for me, sadly, this whole interaction does not affect sales numbers and there is no disincentive for Warner Brothers on changing their covers at the last minute. I suspect all that will happen is eventually Amazon will get stingy and stop offering refunds. Caveat Emptor :/