Replaced Food item

I went to John Dory's at Wonderpark mall and i ordered the Cajun Chicken Stack and some chicken livers for take away. I asked the waitress to substitute the chips on the chicken stack meal with a salad. Firstly, they brought me the bill before i even got my food. It was odd but i thought noting of it as i thought they just want to speed things up. Then i finally got my food and left, when i got home i found that they put fish instead of chicken in my Cajun chicken stack and nobody bothered to tell me if they are out of chicken or if i don't mind the fish. All the other ingredients for the stack were correct except for the chicken which goes to show that this was done on purpose. I'M NOT HAPPY, i expect to get what i ordered and paid for. Even sad because i tipped the waitress as well