I don't need/want SA's fawning over me but that would've p*ssed me off, big time. Doesn't matter that it was a high-end store or that you're returning something. That was just really poor service. I don't know what it is about Barneys, I was at the BH store last week and in the space of the size of my (not large) living room there were 3 SAs, NONE of whom helped me even though I spent time perusing the bags, trying them on, etc etc.
Contrast that with Bloomie's, I stopped by there on the way back from the gym (!) to return something and the SA treated me like I was a celebrity, offered to presell the jacket I was buying, gave me her card, sent me off with a smile even though I was totally grubbing it in my sneakers and baseball cap!