Steering Rack And Pinion problems of the 2015 Chevrolet Impala

On 11/20/17 my wife was driving our car, taking one of our daughters to school when the car sounded an alarm and message of "power steering failure - drive with caution" appeared on the dash. She was on a city street and moving, but needed all her strength and body weight to turn the wheel. She had the car towed tot he dealer, who advised that their was a total failure of the electronic steering rack and pinion system, making the car unsafe to drive. Further, the parts needed to repair the condition are apparently on national back order, and as of this writing gm/chevy is not responding to my dealership's request for an eta on the needed parts. I am being told my car will very likely be kept through the new year. I am very concerned as this is a major safety issue for my family. Further, if these parts are on back order, and gm is not responding to the dealer with an eta, that tells me that this is likely a wide spread problem. I do not want my car 'repaired' with a faulty design or part that may fail again, creating a dangerous situation.