How mature is my director??

I work at a daycare and my boss just sent me a FACEBOOK MESSAGE saying that my position is now ceased and I have to leave. I was a casual and was actually supposed to be done on the 27th anyway, but isn’t it still immature that they would say that in a Facebook message instead of talking to me face to face?

****** UPDATE******

Now she won’t even give me a paper that is needed from her and that can prevent me from doing any future jobs involving child care.

I even asked her if I could come in to get some of my books that are special to me and she refuses to let me go.