I Hope Your Mug Shatters Into 1000 Pieces

So I work at an amusement park as a merchandise associate, which basically means I’m a retail sales associate who works without AC a lot and gives directions even more. Anyway, in my shop we have these mugs with names on them, some of the mugs, located on a specific shelf, are $4 instead of $10. The sign clearly says “select personalized mugs $4.” Well, here comes this lady, over 40, tan as heck, with like 5 that she thinks are $4 each. I tell her that unless they’re from The Shelf they’re $10 a piece, I even walk over and show her that the sign says “select mugs” not “all mugs.” She wants to know what the difference is and why certain mugs are cheaper, all while going on about how ridiculous this is etc etc and using the rudest tone possible but of course I don’t decide what goes on sale when and why. She puts the mugs back, comes back with one, it still wasn’t one of the $4 mugs, and when I told her this she got in my face: “Nooooo I got it from over there” -she points-. I explain that she still doesn’t have a $4 mug, so she leans into my space and tells me to call my supervisor. I do, and my supervisor said to give it to her for $4. When I told her this she still wasn’t happy: “That’s not THE POINT.” she said. I asked if she wanted it still, she said yes but she really wanted to talk to a manager “but apparently she can’t be bothered, and I know YOU don’t care.” Well no I don’t care about some woman twice my age in my face when I’m just trying to do my job without getting written up again. When it came time to hand her her change I slammed it on the table along with the receipt and didn’t give her a bag until she asked for it. By then I’d already dealt with a few more-than-typically-rude guests, not to mention a childhood of bullying and being a doormat, so I’m done turning the other cheek and being polite. To my display she said “Wooow, you’re going to be working at [amusement park] for the rest of your life little girl.” I’m going to be a senior in college this year, I’m majoring in English and double minoring in Spanish and Journalism. I have an editing position with the school paper and have already done two freelance editing jobs. A combination of bad luck and a need for money led me to my current shitty summer job.I just said “Ummm, I don’t think so” The bitch goes “Oh yes you are with that attitude, slamming my money around like I did something because I made you call somebody, I guess that was too much WORK.” I’m on my feet 10 hours a day, often in the heat without AC, typically running entire stores by myself without the power to refund, exchange, or cancel a transaction halfway through (all of which are very necessary on a daily basis). I just said “I’m not the one getting an attitude with minimum wage employees who don’t control prices.” I don’t really remember what she said next but it included the words “I know you don’t set the prices, it’s not your fault it’s not my fault…” I just remember thinking that if this woman realizes that there’s nothing I can do to change the prices what the fuck did she think she was accomplishing by being so rude and literally getting in my face? Before she left she looked at me expecting a goodbye, and told me sarcastically to “have a nice day” I responded with just as much sarcasm “you too” and later wished I had started off with “have a shitty day and please fuck yourself with a cactus.” My only satisfaction was that I didn’t start crying until after she left, and then later when I was telling my mom and brother about the whole thing. As of me writing this I still work there, but this is the third time I’ve cried on the job in almost as many weeks, I got close to a panic attack one day, and I’m completely miserable the entire time I’m there, pretty sure my two weeks’ notice is coming in soon.