Working in Food Service SUCKS

Okay I have a work story. I don't wanna be too specific about what my job is because i don't wanna get doxxed, all you need to know is that part of the job is making and selling ice cream. So today a girl that looked to be about 16ish came in and ordered blue moon. She paid, I made the ice cream, and gave it to her. I waited for her to leave, but she stayed and took a bite of the ice cream before saying, "ew, this is not blue moon." And I just politely replied, "it is, actually." Then this girl rolled her eyes and told me, "this is not as good as the blue moon I had at [place]. You did it wrong." I like to think I don't get offended that easily but this girl was really pissing me off. I apologized for her disliking of our ice cream with a strained smile, expecting her to just throw the cone away and leave. Instead, this Teenage Karen asked, "Can I just get a different ice cream to replace this one?" At this point another one of my coworkers was with me, and she answered, "we can't just give you a free ice cream, if you want a different flavor then you have to pay for it." The normal, mature response to this would have been, "oh, okay! I'll just leave then." but this girl threw a whole tantrum because her ice cream was gross and she paid for good quality blue moon ice cream. I just stood there unsure what to do because I've been yelled at by customers before, but I've never witnessed someone just freak out over something so ridiculous. My manager came and told us to just get her a free ice cream, so we got her some vanilla to calm her down. She took it and just angrily walked out. To make this story even worse, her mother was there the whole time just watching her daughter harass two teenagers out of a free ice cream. She did not seem to care at all about what was happening. Anyways, that was my day today, how was yours? I could use some funny stories to help cheer myself up. Also - important note if anyone out there actually reads my blogs, I'm going to be offline next week so don't expect any new entries :P