Driveshaft problems of the 2016 Jeep Grand Cherokee

Car was purchased as a certified pre-owned on Feb. 2018 in preparation for our retirement vacation. We drove it locally for a couple of months and then set out cross country on may 15th. We drove to massachusetts without incident, then headed back west near the end of June. No problems until we reached idaho, where it started vi rating and making clunking g noises from the rear. We brought it in to rogers Dodge in lewiston. Their service advisor test-drive it and said, you can't drive this car, it's unsafe!" they removed the rear driveshaft and drove it again, noting that the vibration and clunking were gone. The conclusion being that the rear driveshaft was bad. They attempted to order one but found out driveshafts were on national back/order. This made me suspicious. They finally found one and had it installed about 1&1/2 weeks later. We drove home. A week or so after that we drove to California to visit family. We had accumulated about 2000mi since the new driveshaft was installed, when it started clunking again. We brought it in to lake elsinore cdjr and they diagnosed another bad driveshaft. They submitted it to Chrysler for warranty repair but Chrysler decided that the repair in idaho must have been done incorrectly, therefore no warranty. I objected to this. Once again, there was a national back order on the driveshafts. This time it took two weeks to obtain one. When they installed it, it broke while their mechanic was test-driving the car. From there, the dealership had no idea what happened, so finally they had their body shop look at it. The body shop manager said that it appeared that some minor damage had happened to the front of the car and was repaired before we bought it. However, he couldn't explain why it broke the driveshaft. I spent the last 2+ weeks pleading with Chrysler care. Now they tell me the chassis is off by 1/4" so they can't warranty it.