You could have done some dirty trick when you found out you missed deadline: just call the rebate company inquiry about the status. rebate company will say they do not have information. Then you play innocent claimming that it got lost in the mail. Then ask how to re-. You have to re- with copies of your material (not the original stuff), otherwise how could it lost in the mail but you still have the ORIGINALs?
This time, you are out of luck now.