So many...
Young guy came into my shop with his gf, stood looking at the 2m patisserie fridge with approx 30 different cakes in, then asks at the till "do you sell cake?" Being kind, I reckon he was on a first date and super nervous!
Woman making a big fuss about us not having soya milk, offered dairy or oat but she couldn't have either due to allergies then also orders a caramel (made with condensed milk) oat Flapjack. When pointed out it contains both dairy and oat she said it would be fine.
Several times, again referring to the huge selection of cake, "is that all you have?"
Two women come in to the cafe, one orders a coffee, they set up lap tops then get out their own packed lunches. I obviously tell them they can't eat their own food in here, "but I've bought a coffee!"
At a garden centre, an offer on ladies tops. Woman comes to the till and says she bought them last week before the offer, could she have a refund. I say that yes, I'll refund and she can buy them again...she didn't even have them with her, no receipt, but still wanted me to refund and couldn't understand why I wouldn't!
Woman bought a dead plant back for a refund, different garden centre label on, again a big fuss about why we wouldn't refund.
Car wash, customer came back annoyed there were water runs on his car, couldn't understand that we couldn't dry it 100% and some water would run out when he started driving.
Best one at the car wash, guy parked on the run up to the wash area. I went and very politely said he couldn't park there. "I'll only be 5 minutes" he says, to which I point out it doesn't matter, he's blocking the way in to the wash. "You're very rude, I'll have you know I know the owner!" I was the owner, and no, he didn't!
I've worked with the public for decades, luckily now for myself so I can be very honest with them!