Disgusting service at Steers Dainfern

I went to Steers Dainfern yesterday and ordered a vegetarian burger and chips. I sat at the restaurant and waited for my meal. After waiting for about 25 minutes, I was approached by one of the kitchen staff and was told that they did not have stock of the burger I ordered. I asked the lady why it took so long to realize that they didn't have stock. She in turn called the cashier that took my order and I was told that the manager will come to speak to me. After waiting quite some time, he appeared from the back of the store and asked me how I am. I stated that I was angry and he laughed it off. I really did not appreciate the service received and attitude of the staff. I received a refund and left. I also logged a complaint on the steers website and have not received a call as yet.