Disappointed - Marmot Never Summer 0 Sleeping Bag -600 Down-

I've completed 2 thru hikes on the A.T. and have a lot of backcountry and gear experience. I bought the Never Summer sleeping back and I have to say I am disappointed. The loft of this bag when I first looked at it was less than i'd expect for a 0 degree bag and that turned out to be true. I've had it in weather down to about 18 degrees and I was NOT warm while wearing fleece pants, tshirt, and heavy weight fleece sweater and sleeping on a sea to summit insulated inflatable backpacking sleeping mat. I want to like this sleeping bag but am pretty disappointed. I don't see how it could possibly be considered or labeled a 0 degree bag and I've owned multiple 0 degree bags over the years. Not only is not warm enough to be down to 0 degrees, my first night in it I awoke the next morning with quite a few feathers all stuck to my fleece sweater. For the price I would think it would not have feathers falling out and it would be warm to the rated temp. I personally would not use the bag below 20 degrees if I wanted to be comfortable.