Redhawk, if they sent them to you in error, you don't have to pay return shipping...just notify them they screwed up the order and to send you a prepaid return shipping label, a UPS pick up 'call tag', etc...done that several time over the years.
Odds are they won't even bother paying the return shipping, they'll probably just tell you to keep them, and they'll also send you the correct box of .490's