Front Air Bag Sensor Control problems of the 1998 Cadillac Deville

There was a recall on the airbag sensor of my vehicle in 2000. I was not aware of @ that time because I had not purchased it from the local dealership yet. On Feb. 16,2015 I called the 1800. 458. 8006 & was told that I would have to pay to have the part diagnosed & fixed if needed. The rep. & I went back & forth as to who should pay for this etc. ,. I called again on 2-19-2015 spoke with another rep. Still got the same answer. Basically I was told that the recall was closed out in 2001. When I asked both reps. That I spoke with if that meant there was a expiration date, I was told no. There were other questions that I asked in reference to the matter that does not add up between each rep. & the local cadilac technician that the first rep. Connected me with. I need help in solving this problem. The case # 71-1431796328. There are other factors I documented if needed.