Rite Aid

So I went to several Rite Aids today.. and after two that didn't have what I wanted in stock, finally the third one had mostly what I wanted. So I have my cart full of Gains, Pantene, Nivea body washes, etc, and headed to the register with my coupons. I get there and handed my card and waited for her to scan all my items. I then handed her my coupons, with my $4/$20 VV on top. She separates all the coupons to match them to the items and then says that I can't use the Boudreaux's VV $3 coupon with my $2 manufacturer's coupon because that would exceed the selling price $3.99. I didn't want to argue about that so I said fine just use the $3 one then. She scans the rest and I said you forgot the $4/$20 VV. She starts to get pissed and asks what that is like she didn't know what a $20 purchase meant and why didn't I give her that first? I said I put that on top of the stack! She then prints out the receipt and complains that she would have to cancel the whole transaction and start over. I said fine, I don't want them anymore, give me my coupons back. She throws them at me very rudely and I start to count them to make sure I get all of them back. Meanwhile, she says, "It's always YOU PEOPLE. You CHINESE people always want free stuff." If that is not ignorant and racist I don't know what is. I storm out of there with my coupons. My only mistake was not getting her name. But I know she was the shift supervisor there so I will be making a call to customer service first thing in the morning. I don't understand how she can have a job in that position and treat customers without any respect!