Genuine friend. This is the nature of life and people..

In english we call them very fickle.

Its something very wrong and we should love each other as we love ourselves. And never look down on another person and think we are better than others. 

have you tried telling your friend how you feel. And maybe she has an excuse for her actions or didn't realize she was hurting your feelings.

At the end of the day.. it doesn't really matter though.. This life is so short and soon little things like this will hardly matter anymore. With every hardship comes relief,  so struggle and be happy with the many blessings we have been given and have yet to be given.