Ooh, so many. I work for London Underground.
"Why does the Northern line go south and the Victoria line go north from Euston to Kings Cross? This to too confusing, please change it."
(Walk, it's five minutes down the fucking road).
"I need to get to Leeds in an hour. Why does it take three times as long and what are you going to do about it?" (I am not chartering a helicopter, we run on public funding)
"I want a three day travel card on a paper ticket and a receipt." When told no such ticket exists and he'll need to use contactless or an Oyster card, "Your head is full of shit. You don't know your job. I got that ticket ten years ago the last time I came to this country. You are full of shit." (Things have moved on in ten years)
When offering to help a woman's "kids" through the barrier, being told, "They are not KIDS. They are children. Use the right word, you uneducated imbecile."
Being shouted at because despite offering a bus to the nearest step-free station, a woman complained there was no lift. TfL cannot put a lift in said station because it's grade 2 listed. We generally offer other step free options including buses, but this woman was anti-bus claiming they are full of "poor people".
A man insulted my marriage, my sex life and my mother when I refused to put a discount on his Oyster card, because he didn't have the right ID.
After 7/7, a man shouted at me because the Piccadilly line wasn't open. I said, "it's a crime scene so the police need to forensically investigate,it takes time." "I don't give a (bleep) about that, I need to get to (station)." More than 90 people died in that attack, but he didn't care.
I could go on. I have been doing this for 17 years. Despite the arse holes and unthinking selfish idiots, it's a good job and I cannot get anything comparable in the same industry for the same salary.