No disagreement here. My point is that when I asked for a 1-series the agent informed me that they are not available (this is fine), but then proceeded to offer cars from lower tiers which I feel is a bit dishonest. I specifically chose to pay extra for a higher-tier car and I'd expect to receive what I paid for.

Again, you're absolutely correct, but it goes back to the point of the honestly and transparency. I should be clear to the agent that as holder of non-German passport and someone interacting with the agent in English it would make sense to provide an English version of the agreement. When I rent from Avis I never have this problem. I this specific scenario, after having to wait for so long to get the car I was frankly just fed up with the process and wanted to get out of there as quickly as possible.