I doubt it happens often, sounds more like a combination of self victimising and entitlement on your part. In fact it also sounds like you're only being her friend to try to shag her, so it's odd you feel hard done by.
Friendships can be unusual, I have an attractive female friend who is very cuddly/affectionate, but we've always had an understanding. I know other people may have thought there was something going on or that she was leading me on, but we've just always been like that. Some girls just have a flirty nature, it doesn't mean they're leading you on.