Have u smelled it before? That's a good way of telling if its legit, as well as the longevity, Angel is one of my favorites for sure and I get at least 8 hr on my skin. The reputation of the seller, the priced you pay, many clues will help! Also, post pictures, the guys here will help you!
And to refill it look at the bottom of the metal cover, you can unscrew it and remove the bottle inside. So when you run out just buy a replacement and put it back inside the metal container, pretty clever huh?
Oh yes, And welcome to Basenotes!!