My brother wanted to go grocery shopping, but he wanted to go to a grocery store gas station rather than the grocery store proper. Solely because the frozen burritos are bigger, despite everything costing a lot more in the gas station. He'd called to see how much was on his debit card and heard seventy dollars when it was really seventeen. But he doesn't know this until we check out.
He walks up with an armful of stuff and the cashier starts to check him out. I start to hand her a reusable bag but she's already putting stuff in plastic bags. No big deal, she probably didn't think we were together. So she puts the stuff from the plastic bag into the reusable one. She fills it, I take it, and a bag of Andy Caps hot fries falls out. So as I hand her the other reusable bag for the rest of the order, I throw the bag of hot fries that'd fallen on the counter into the empty. She doesn't like this, pulls it out of the bag, reaches across the counter to jerk open the one I'm holding and throws it in.
She finished the order and then comes the customer suck as my brother's card is declined for insufficient funds. So he pulls some energy drinks and frozen burritos out and asks her to take them off. She does and he still owes twelve cents. He says "I think I have that out in the car" and runs out, leaving me at the register to apologize. She's visibly grumbling and annoyed. He comes in a minute later and says he doesn't have the change and asks if she can she take a soda off.
She loudly exclaims "FORGET IT" finishes out the order somehow (I'm guessing the amount debited had already been approved and she did the twelve cents as cash), and sends us packing without a receipt. And the kicker? She hadn't even removed everything from the order my brother had asked her to, as she threw a couple of the burritos into the bag.
I get that my brother was annoying about the change and taking stuff off an order, as I was a cashier at two different stores, but when they ask you to take something off you take it all off, not just what you want to. And you always remain polite to a customer unless they're being abusive.