Rude people who seem to take delight in screwing their customers over. You can hear the glee in their voices when they tell you no or that you have to pay more money. Receptionist is the worse. Apparently they don't have to be nice because there isn't a lot of competition.
Driving instructor yelled at my daughter. If I wanting yelling, I could have taught her to drive myself. Driving instructors don't give parents feedback or suggestions. When I did get one to talk to me, he was very short & unhelpful.
If you expect pleasantness, friendliness, feedback, help or even general politeness, you will be disappointed.