unfair scam, she messed up my holiday!

I wanted to buy a costume for my cosplay event and found this person, The costume which I wanted was about $1400 so we agreed that I would pay monthly for it. When I did my last pay it appeared that I will receive my purchase after the day when should be my event. She is unfair, we spoke about it before and she knew when I need the costume so we agreed that she would send it before!!
I just waste my money! People beware, please beware!