bad service

I ordered a beef burger combo & a lamb burger combo they made the beef burger right then I was waiting for the lamb burger. The lady that made the burger asked me what I wanted on my shwarma, I told the lady i ordered the lamb burger, she turns around and said they don't have lamb burgers in stock today. After, I confronted the manager, I told him he could of told me they were out of stock. He said \oh I made a mistake"but when I ordered it in the first place I pointed and showed him I wanted the lamb burger from the menu. So I ended up re-ordering a beef burger which I then waited another half an hour for. While waiting for the burger"