Derby Food Center Overcharged, refused to give receipt Berkeley California

The people that worked there were rude every time I was there when i asked to see the liquors behind the counter. One time I asked for the ciroc. I bought the small 375 mL as I didn't know if it would be good or not. He rang it up and told me it was somewhere around 40 dollars. I paid with debit card but it didn't seem right about how expensive it was. I wanted to confirm by looking at the receipt as there were no price tags on anything in the store. I put out my hand and he refused to hand me the receipt by just saying "bye," in a way similar to "leave." I checked online and the small size of ciroc is about 16 dollars.