Very bad customer service

I went to Pedros Centurion Mall today to buy 1/4 paella and my order number was 333. I sat there for more than 30 minutes waiting for order. I got tired of waiting and went to the cashiers to ask how far is my order? The cashiers answer was 'sorry sesi, we did not have chicken'. What a pathetic service!!! Why didn't they let me know they don't have chicken first thing when I place my order so that I can decide whether I wait, order a different meal or move to the next restaurant? Only to let me wait and later tell me they don't have chicken? They have wasted my my lunch time, petrol and parking fee for nothing! They then tried to give me another customer's order and I opted for a refund as I was no longer going to enjoy my meal because I was very angry!