Since you already replaced the vehicle just wait them out. Even if it takes a few more months. Most people who have had this happen don't pay anything for the replacement engine. Even people who were at non BMW repair shops. This is the exact situation shop insurance is for.
Mileage is irrelevant if they did something wrong that starved the crank of oil. Did they take apart the engine to determine the cause of the failure? Probably not as it is not easy to get the oil pan off the AWD.
|