Received Wrong Computer

I purchased a 17.3″ HP computer. I actually received a 16″ computer> The serial number on the box indicates that the computer should be a 17.3″ computer. When I realized that the computer I received was smaller than the one I paid for, I contacted HSN customer service and was told that my inquiry was past the 30 days and there was nothing they could do. Is there anything I can do? I believe the 16″ computer is about $200 less.