Thanks for your replies, guys! Ok, I took the pair to a shop which carries Blue Cult to authenticate it, and it turned out to be FAKE!!! Now, I am definately going to return it, but I don't see why I have to pay shipping and returning fees for Bluefly's fault.
Anyways, I need to get an official letter that states this pair of jeans is not authentic in order to get a full refund to my credit card, NOT as its store credit. Why do I bother to do all that? Because I cannot stand being cheated and ripped off like that, if you know what I mean?
Before I purchased it, I did check Bluefly's reputation, which was pretty good.... If anyone is interested, I don't mind posting pics of it.