Front Air Bag Sensor Control problems of the 2008 BMW 135

My vehicle is a low mileage (36k) well maintained car. My local dealer replaced the driver air bag under a recall June 29, 2020. Shortly after within 250 miles/2 months a srs/air bag system fault/warning started happening. It was diagnosed as a faulty pass occupancy sensor that they want $3600 to replace. Unfair, there have been several pass occupancy sensor recalls for other models of the same vintage (2006-2008). This should be covered under the 15 yr extended limited warranty offered to other BMW model owners.