Why are dealerships so reluctant to update/reprogram my transmission software? They keep saying that if there are no faults when it is scanned and if they can't replicate the problem, they can't update the software.

I have a 2006 X5 4.8is and I've taken my car to a couple local dealerships to let them know that it gets stuck in a low gear when going down a steep hill causing it to rev reallly high and won't upshift properly. I can't replicate this problem when my E53 is at the dealer because there aren't steep enough hills in my area. However, I make frequent road trips to visit my parents who live in another state. It is during this drive when I encounter very steep hills on the highway which is in the middle of nowhere.

All I want is a damn software update to see if it resolves my problem. Should I call up non local dealers and ask if they are will to update the tranny software for me and then make the drive to have it done? My car is still under full factory warranty.