What do i do when a girl says she will talk to me soon via text but doesn't?

Go to her house and check if she is there, if she isn't she might be busy, or off with some other guy, if she isn't home you need to wait til she is, and hide somewhere, when she gets there look at her, see if she might have been with a guy, if she was you should kill her, I recommend burying the body near her house, delete any messages on her phone and return home, this never happened.