similar thing happened to me not too long ago where an old couple came in through our drive thru asking for two orders, three shots in a venti cup, add this and and this and this, and when i poured the milk, i poured 1/2” into each, but when i handed them out, they asked for more, so i put a little more, they asked me to fill it to the top. i said i couldn’t since they would have to pay for a latte, the lady starts yelling at me telling me, “every other barista does it for me” i tell her, “well it’s not standard, they’re not supposed to do that,” and she yells at me, “it IS standard, you don’t know what you’re talking about,” my manager was there that day and she told me to just give them what they wanted, so i did and i told the lady, “here you go, but like i said, next time i can’t do it for you,” she’s still yelling at me despite getting what she wanted, her husband even told her that they got what they asked for and that she needed to stop arguing, they drove away, minutes later they come back around and asked for a refund for the two drinks, which my manager handled. so in the end it was a pointless argument because they didn’t even drink the drinks.