diwali offer

i had baught hp notebook on 2-11-2011 during diwali offer from HP WORLD@TREND MARKETING next to mahanagar nursing home B 939,SEC A, MANDIR MARG ,LUCKNOW and at that time there was offer of nikon camera on the notebook which i had baught ....... i had sent a cheque of rs 2499 to H.P. redemption cell Solutions Integrated Marketting pvt .Ltd and now after so many days hp office has sent back the cheque instead of the camera ............. now pls tell me what cn i do to get the camera ,............ if nothing is done and if i dont get my camera then i will surely complain in consumer office against H.P ........... so pls give me solution to my query........ my complaint code is 4690381880