Air Bag Light On problems of the 2013 Mazda MAZDA3

I was driving on the freeway at approximately 65 mph when all of the sudden I noticed my airbag light began blinking while in motion. I did not brake excessively and I did not hit anything or swerve. It jist randomly lit up out of the blue. Then I noticed my passenger airbag sign was off. I called the Mazda dealer and they quoted me $160 jist to diagnose the light. I told them I got a postcard about an airbag recall and they insisted my car was not covered in that recall. It should be.