I probably echo this quite a bit on this board but it's only because I think it's excellent advice when it comes to relationships: "When people show you who they really are, believe them."

Your friend chose your clothes over you and when you gave her a "hard time" about it she decided that you were too much of a pain in the ass and dropped you.  Your 15 years of friendship couldn't stand up to a few articles of clothing, and that's sad.  She kept your clothes, she lied about it, she knew she was caught, she made excuses, and then because you finally called her on it she acted like YOU were the one in the wrong.  It's sick, really.  I'm so sorry for what you feel you lost out on but I do think over time you'll realize that those memories are of someone she used to be and not of what she is anymore.  She changed and chose her road, she showed you what she really was, and you'll be better off knowing it now than wasting another 15 years being a friend to someone who treats you like crap.

I am really sorry you got hurt in this.  pets  I hope that she does contact you again just so you can get some kind of closure out of it.