Chef Refused To Make Order

I visited the Ocean Basket at Cape Town International Airport today. I placed an order for Sushi Take Away (8 pieces) and paid. I knew it would be a while, so i walked around. 10 min later I returned to the restaurant and the waiter told me my order is almost ready. so I accepted this. 5 min later I went to check on my order and the waiter apologized the chef didn't even start with my order (I'm not sure what his problem was but It had nothing to do with me). He refused to make the order immediately for some reason. So the manager came to see what the problem was. I explained. Then I asked for a refund and they refunded me because I had already been waiting for 15 min already. Thereafter the manager left, without explaining why I didn't get my order or even A simple Apology! (The manager probably has a problem apologizing to people of Colour?) This is real ****ty service. I will definitely think twice about recommending this Branch to any friend or family member. All of this happened and the restaurant was not even busy. So I cannot understand this!