They don't care about customers

I ordered 2 Wacky Wednesday as I do normally do on Wednesdays. I went to Spur bought stationery. When I returned to Steers, my order had 1 Wacky and they gave the other Wacky to other customer. They ignored me when I enquired about other burger, asked why do they give other customers special treatment. I left as I got angry came back after cooling down. Asked for a refund they we happy to give me a refund they thanked me instead of apologizing. I even asked if they will apologies or not? I buy there all the time since the shop is close to where I live. I just don't understand why do give part of my other to someone else and ignore me when I ask. They didn't care about complain. I was expect an explaination and apology. This has distracted my preparation for the exam. Since I was mocking the exam and timing myself for paper 1 lunch paper for fitness. I failed to test my fitness since I'm writing the exam tomorrow for whole day. I felt disrespected by their attitude.