Yes, they are totally authentic! But my advise to be carefull with ANY store that accepts returns. Some people scam the stores by purchasing authentic items and returning identical fakes. I know a guy that buys fake Rock & Republic jeans & returns them to department stores all the time.
Filene's Basement is completely authentic; they've really raised the bar on the types of items they carry now (i.e. BV bags, Cartier watches), which made me a bit nervous, but I've never had a problem.
However, as the recent poster said, you do need to be careful of returns and switches, so I'd post anything you have a ?? about here.