I've worked in retail before. Once at a place that sold drinks. And the other at a general candy store at my school.
A few things that i've noticed.
1) If you don't know who they are, THEY do not know what they want. This usually means that you have to answer questions. Sometimes lots of them. Usually, I was willing to be patient for the drink job, but not so much for the candy store since the already long line would then be proceeded to be held up.
2) Signs are invisible. Seriously. I don't know how many times i've had to answer questions where the answers were literally right beside the customer. It got to the point where I just made prices up for the candy store. Another sign people don't seem to understand is "closed." I remember during the xmas party at the drink job, people would bang on the doors of our building and ask if we were closed.
3) The whinier the customer, the more they think they can make you lose your job. Not so much an issue with the drink job, because anybody who was a real dick was dealt with by the head of staff. But it's incredible the number of high school students who thought they could make me lose my job at the candy store. "I'm going to get you fired" was a pretty standard thing to hear. This one was my favourite, because it'd then be followed by "I want to see a manager." Which I got to say "You're looking at a manager." Or things like "i'm never coming back." That's good too. Especially when you see them back within a week.
It's really unfortunate. But I always try my best to give service industry people a break because they really do take loads and loads of shit. Most of my friends have great service industry stories.
Basically, just because you are buying something from the place, doesn't mean you get to be rude to the employee.
And your hair looks excellent LPM!