This girl at the register seemed to have no idea what the woman she was talking about.
MAYBE, this could have been better handled by the more senior employee kindly asking her again what the issue was, and try to make it right. She was dismissed without anyone trying to understand what she was upset about, how they could make it better, or even an "i'm really sorry this happened and you had to come down here to figure it out". Also, I can only imagine how many times a day this happens all over the country. People are having difficulty dealing with people.
Also, also... whip cream on a snow cone?? Nope. ;)