Can a cashier refuse change? What gives?

Yes. They have no obligation to break a note for you. Why should they? If you are buying something, they'll give change but they are not in the money changing business.

Need to buy something. Private property. They can't open the drawer without a sale.

Stores are under no obligation to provide change.

yes he dose. he needs it to make change for people that buy things. what I don't like is the store that wont take $50 or $100

Wow what sentimental issues, remember the phrase you are what you eat.

Of course. Criminals often ask for change before robbing a place.

They can refuse to serve you and as you were not purchasing the 'service' you wanted was from a bank and they are not a bank....so of course they can refuse

Of course he can. One of a cashier's responsibilities is to maintain an operable cash drawer. Not to be the bank for whomever walks in wanting change. It's entirely normal for a cashier to prioritize cash availability for paying customers.

Ha ha, yeah he did refuse it

A store doesn't have to give someone change that doesn't buy anything. Even some banks don't give change unless you have an account at that bank.

If the cashier doesn't have change, then of course he can.