Hatchback/liftgate Support Device problems of the 2006 Subaru Tribeca

I have a 2006 Subaru b9 Tribeca and the air cylinders that are supposed to hold the rear hatch open fail in cold weather. I live in mn so since it has gotten cold, the hatch has fallen on my head several times. Once it dropped just as I was walking around the car and it hit my forehead so hard that it bled and made my neck sore. This may not sound on the surface that it is a serious defect, but don't tell my head that. When I contacted the dealrs (2) to try to get this fixed, they said the parts are on backorder and they are not sure when they'll get them. The date below is not correct because you didn't have 2006 in the drop-down.