Slow service and rude staff

Got to the cafe a ordered within the first 5 minutes of being there. After waiting for my food (a sandwich) for 40 minutes, I called my waiter to ask when my food will be ready, he said that it is almost done. I informed him that I’d like the bill to pay for my cooldrink as I have to leave for work. He then came back with the manager who then told me my food is ready. I told her that the service is very slow and that waiting 40 minutes for a sandwich is unacceptable. She then rudely told the waiter to “bring this girl her bill”. I paid and left feeling quite upset after being belittled and treated so poorly.