Ups is my go to. But I do not tell them what I'm shipping. I understand their policies, and also understand that they often have a poorer grasp on them. I also understand that obscuring what I am actually shipping could be problematic were something to happen to the package. But this is how I currently ship anything I have to.
That said, if I had the intention of telling them, and encountered the same person and situation... I would have quickly turned around and left.
Nothing like someone that thinks they know better and are "in charge" to wreck your day.