The most infuriating type of customer when working part-time at a convenience store

People who throw items or cash at the counter
It feels really unpleasant when you experience this
The worst one was someone who threw banknotes almost like they were scattering playing cards
Lately, most of these people are either elderly or elementary school students
I want to swear right in their faces, but I just throw the change back at them the same way and let them go