Engine Shut Off Without Warning problems of the 1997 GMC Sonoma

Approx one mile from home as I was approaching a stop sign engine suddenly shut off. After a few seconds managed to restart engine. Engine shut down twice more before arriving back home. At home was unable to restart engine had vehicle towed to GMC/Buick dealership. Dealership found that problem was defective ignition switch assembly. Replaced ignition switch at a cost of $600. 23, I was informed vehicle was not on current recall list. If not, why not. Thank god I was not on interstate with a 16 wheeler behind me. I contacted GMC customer assistance requested to be reimbursed for above cost. Request denied because vehicle not on recall list. I also have a 2004 Cadillac which is on recall list for ignition switch never recieved recall letter until I complained at above customer service they did send me recall letter concerning Cadillac. Unable to have switch repaired because Cadillac dealer cannot get parts.