I had the same problem with a very hard trigger pull with my C9, I called Hi-Point and they said to sent it in. They took care of it.
See my post about when I got it back here: http://www.hipointfirearmsforums.com/Forum/index.php/topic,22159.0.html
See my post about when I got it back here: http://www.hipointfirearmsforums.com/Forum/index.php/topic,22159.0.html