Not as far as I remember.
Probably because I don't buy things much often since I'm a dirt poor. Plus, I wasn't really aware when they give me the money I should get, in the past. They could've rip me off a few bucks and I probably won't notice. Hopefully, I've become much more careful and observant when I interact with people. Whether it's shopping or not

To the contrary, there was a few times where he/she gave me too much money than I should normally get. Of course, sometimes I shut the hell up but I try my best to tell them when they don't gave me the right ammount. Yea, I'm nice like that.
The funniest one was when I bought my Yearbook. I came and asked for one. The woman got randomly distracted by somebody else while I was asking and she completly forgot to ask me the money. But because I knew her, I did tell her and paid it anyways. But I find it funny that I could have got away easily without paying.