Dollar General

I went in the store and check out at 14:23:29. I gave cashier a $20 bill and got my change back which was 19.05. The lady (white) turn around look at me and the cashier and said, dont do that no more and rolled her eyes. I asked her did she want me to put it back. rolled eyes. She act as though she prejudice. Casher explain to me in nice matter. Mad him Manager for his customer service. I have already submitted a complaint via phone today at CS at 2.28Pm today.