Owners/service Manual problems of the 2010 Buick Enclave

While driving up in a parking lot on an incline structure the vehicle was in drive began rolling backwards and almost hit the car behind our vehicle. We've tried it on several inclines and it always rolls backwards in drive. We have contacted several Buick dealerships and was told that it was just a characteristic of the vehicle. Went to another dealership to have them look at car and was told that I just have to drive it like I would a manual transmission (using both feet) to brake and prevent it from rolling backwards. I don't feel comfortable driving this vehicle with that problem. Safety should be a priority and if indeed this vehcle is known for this problem there should have be resolution by now.

Vehicle rolled back while on an incline (parking structure). It was in drive almost hit the car behind it. It has done this on several occasions since then. Called Buick dealerships in area was told that this was a common characteristic of this vehicle. Took it in to service dept. And was told the same thing also, told that we should use both feet like a manual transmission.