Dollar General review: went in to buy a 18 pack of busch beer sign on cooler door said $9.50 lady at counter said she couldn't give it to me at that price. ?

Was going to buy a few things for hurricane and grabbed a 18 pack of Busch beer got everything else went to checkout and lady said beer wasn't on sale I tried to tell her the sign on the cooler door said it was she said her boss took them all down I told her she must of missed that one and the next thing out of her mouth was I can't over ride it. So I left and was very upset. I didn't purchase anything