Why would I send an ambiguous message to a girl I know but don't know very well? She didn't scold me, just ignored me and didn't return my messages?

You expressed your mind, and your ambiguous information is actually a pursuit. Girls obviously don't like you, so they won't accept you. But in order to take care of each other's face, the best way to deal with it is silence. No response, no result. It is true that you like her, and it is also true that she doesn't accept you. There is no need to scold you. This is another sign that silence is better than sound.