2022 GMC Denali HD supplied camera broke

I just installed this camera that came with my 2022 GMC Denali 3500HD. Since I have a 5th wheel longer that the 32’ recommended, I installed mine just about the rear center marker light on the back of my trailer(the display if fantastic), ran the cable down the back and under the trailer coming up under the nose. The connection to the bumper was ok but there is a lot of slack due to the jack not being inside the bed. Just one trip down the road and the coax broke off at the point inside the rubber sleeve. short of the bumper. I am sure that I am not the only one that has had this happen to them. Shouldn’t this be a warrantee? GM says that this cannot be repaired and hand over another $400.00 and we will send you a new camera. Do any of you have knowledge of how to repair this? And how have you ran your wires to keep it from happening again. Also I believe that GMC should either swap out the be to the bumper connections or put both camera and 7-4 pins in both locations. Your help is greatly appreciated.