employees who don't want customers

Just now I was on my lunch break went to king pie like most days. Asked for a fish burger pie I took 1 bite of the pie & it tasted rotten. Went back & told the cashier(the permenant 1 on duty today didn't get her name but it looked like she's training the other lady) she was extremely rude about didn't ask if I want a refund or another pie just threw the money on the counter & helped other customers then I said but I wanted another pie roughly grabbed the pie I wanted & left it on the counter as if she was feeding a dog. I took my money left the pie there & came back to work as I was too upset to even eat. The attitude was pathetic and other customers witnessed it. I'm a regular customer I should know if something doesn't taste right. Totally digusted. She should not work in a place she's frustrated in. She looks unhappy & takes her anger out on customers which is wrong