Half price sushi not half price

Last week wednesday I went to the Bay west mall branch for half price sushi I confirmed with the waiter that it is half price sushi night and ordered a platter, when my bill came it was not half price.i queried with the waiter, he apologised and called the manager.The manager was extremely unhelpful and told me sorry it does not count for platters she cant help the waiter never told me. Also she told me there is a sign on the wall.i was seated on the outside, far from the wall and was not even taken to be be seated past the wall. I felt like i was just brushed off. AND to top it all, last nite John Dorys bay west mall posted a add for half price sushi night with the picture of the exact platter that i ordered. what a cheak. i commented and got no response. In my eyes that is FALSE ADVERTISING!!i have screen shotted this advert. All i would of expected to rectify this mistake is an apology, void the item and ring up what is on the platter individually so that I can recieve my half price discount! Had i been informed upon placing my order that platters are apparently excluded, just after i confirmed that it is half price sushi night, this situation would of been avoided.