I'm really sorry that this happened to you. This certainly isn't common in NPC sororities, but local sororities can play by any rules they wish. However, if the local chapter on your campus does this with regularity, then they're not recruiting correctly.
Keep your head up, though. From your signature, it sounds like you're already part of at least one organization on your campus that makes you feel at home. Don't be afraid to join others. Greek Life can be an amazing experience, but (like AZTheta said) it's not for everyone, and it's not the be-all and end-all of a great college experience. I had similar experiences of close bonding on a competitive team and a service organization that I was a part of. Your college experience is what you make of it, and there are plenty of ways to find your niche on campus.
Take chances and do things you're excited about!
