FYI: A private person or business entity can't violate or deny you your 2nd Amendment rights.

It also makes no difference whether it's the manager's personal policy or corporate policy. If someone in control of private property tells you to leave (which no one did...just saying) or that firearms are not allowed (which basically implies you need to remove the firearm from the premises) you are obligated to remove the firearm (ie: place it in your car, for example) or remove yourself with the firearm, or risk intervention from the po-po for trespassing.

You can also safely remove a firearm from your person, while holstered. I think you were really stretching on the "brandishing" (which doesn't exist in Colorado...it's called menacing) part.