Dishonor of gift pledge by HP

I purchased ultrabook HP envy XT notebook serial CND2290KQ8 (with a free Nikon cool pix camera Diwali gift offer from HP ) on 12th Nov and got registered with redemption site with redemption code 5427970 on 15th Nov .The verification documents sent by me were received by HP on 30th Nov .HP rejected the offer on ground that documents were received late though the registration was done within stipulated date of 25th Nov.
I can not find now any web page where the valid date of document or the clause of rejection on ground of late receipt was mentioned.E mails in this regars to HP has not met with any reply information except the statement that late receipt is reason of rejection.
Why HP had chosen a date for redemption so close to 19th Nov(end date of sale fo rDiwali gift}if it was promoting its product but customers are getting deprived due to this inappropriate short time limit.Need less to say many customers like me have purchased the product for its worth and promise which HP will keep by honoring the free gift.
I am now disapointed.