I returned to the shop later that day with my mum to buy dinner and was served by a young woman with all the charisma of a drowned gnat. She was slumped in her chair and at one point she even rested her head in her arms. I'm guessing she was tired because she also yawned, but guess what? So was I. I still managed to look bright eyed and bushy tailed. But the bad service came from the way she talked. You know that fed-up sounding drawl someone makes when they really can't be arsed? Yeah. That's how she spoke.
EDIT TO ADD:
I just wanted to clarify something in the second suck. It wasn't just that she was tired or having a bad day, but more like "Oh no, I've got customers, now I can't talk to my co-worker." Because before that she was talking to another coworker. I didn't add it because it wasn't relevant to me and my mum's service.