Can I complain to the airline with my damaged bag?

I came off of a US Airways flight from Barcelona to Philadelphia yesterday, and when I took my bag off of the baggage claim loop, I found out some of the areas on my bag were a little dark, some parts have black on them (when it was supposed to be white) and scrapes, dents, and a misshapen front compartment. Plus, it seemed very, very cold when I took it off. I saw other luggage coming around and they also had stain problems. I checked to see how long I had to complain, I have 7 days(6 days now) to say something to the airline. Should I complain or forget about it?