Fifth wheel hitch - rail bending and pulling up truck bed

We had a similar situation with our "RV" dealer. When we bought the rig they installed the bed rails but they only used one bolt per L bracket into the frame. The L brackets are designed to have two bolts per bracket that mount to the truck frame. I never noticed it until I went to take the rails off when I traded the truck in on my new 2013. Needless to say I was pretty ticked off at the RV dealer and called them up. they just made excuses.