Entitlement or Don't even TRY to kill my shopping buzz...

While finishing up placing an order for a new pair of prescription eye glasses (caramel John Varvatos - deelish) in a shop on Filmore, a woman browsing in the shop decided that it was a great idea to ask the sweet girl helping me to drop EVERYthing she was doing to help her "find the style number" on a pair of sunglasses that she was "thinking about" buying. All this so she could go have lunch with her friends and "come back". When the girl did not immediately stop writing up my order and help her, the woman continued to say, "Excuse me. Excuse me. EXCUSE me." Finally I turned to her and said, "Can you NOT see that she is helping me right now?"
"Well, can't she just answer my question? I mean, can't she do two things at once?"
To which I replied, "I'd never presume that of anybody." and turned back to the salesgirl who was sheepishly trying to hide a smile.
The rude woman continued speaking to my back, "You know, it's a SAD, SAD world when someone can't just be nice and let someone else get a quick question answered."
I continued to ignore her as she went on to say, "I mean, why can't people be nice? Why do you have to be such a JERK??."
I considered going ghetto on her, but instead turned to her and said, "You know why this world is so "SAD"? Cuz it allows people like you to think that their time is more important than anybody elses'."
Luckily at this point one of the other workers decided to intervene and gave the woman the attention she so desperately craved. Having gotten her style number (which I'm SURE she was going to use to find the sunglasses online at a cheaper price), she turned to walk out of the store. As she was leaving, I said, "Have a nice day."
"Oh! You're reDEEMED." was her response.
"I don't need YOUR redemption." I SOOOOO wanted to end that with "bitch", but decided to take the high road.

Now... my question: What in the world could make someone feel so entitled? Was I in the wrong here?
I'm not guilt-free of entitlement. I have to admit it... I feel that I'm entitled to friendly service from a salesperson. I believe I'm entitled to an apology from a waiter when my dinner is taking too long to show up on my table. I feel that I'm entitled to turn down the offer of service from a salesperson in a store that I frequent when my "regular" salesperson is on the floor and I have the time to wait for them to finish up with someone else. I believe I'm entitled to be served when it's my turn.
I do NOT feel entitled to waste someone elses time.