Is that all Miss??

It amazes me how insanely mean and rude people could be. Working in retail can really mess with someone's psyche. I as a cashier work in a clothing store on SOHO and on weekends it's always busy. So I get the particular customer that was so rude. First of all she was on the phone, that really annoys me because their attention is focused on the phone call and not on the transaction that is being done. I greet the customer politely nonetheless and she pays me no mine by continuing to carry on with her conversation. She then paused for a few seconds to let me know that she wanted to return 2 items but she wanted them done separately. So I do the first return as requested and asked, "Is there anything else Miss?" She looked at me and continued her conversation, so I said again, "Is that all Miss?". She responded by saying "Yes! I told you I have another return, I said it twice already." Meanwhile the item that she wanted to return was still in her possession tucked away in her handbag. Already annoyed, I took a deep breath and said. "May I have the item please?" Well apparently I was disturbing her precious conversation because this stupid b*&@ had the audacity to take a deep sigh of annoyance and proceeds to tell the person on the other end of the line, "Let me call you back because apparently I have to give this GIRL my full attention." It is not what she said but how she said it that really pissed me off. She was talking at me instead of to me. I am not some little high school kid, I'm a grown women. It pisses me off that some people think its right to talk to you however they want because "THE CUSTOMER IS ALWAYS RIGHT!!!!" That saying is utter bulls*@t. It took a lot out of me to keep my composure and finish that transaction without cursing her out for being a complete douche-bag.