Regarding dda mig flat

Complaint regarding my mig flat 301 2nd floor in sec 19 dwarka Sir/Mam, My grandfather Sh.Som Nath Talwar had applied for Mig flat vide regn no. 29082 under nprs scheme in 1979. While further enquiries with DDA informed us that there is no allotment of flat against the same.We have then gathered that MIG flat no 301 ,2nd floor has been allotted by DDA in 2003 in sec 19,Dwarka. We also gather that demand note /intimation letter was sent by DDA to the following address: 119-97 , Gali Samosan, Farash Khana,Delhi 06. We have recieved no intimation/demand note from DDA since it was sent on our old address.We had informed DDA about change of address vide letter date 22/12/88 which was recieved by your dept on 6362 ,dt 22/12/88.Our current/new addesss is: 244A/26 Pandit Park, Shivaji Gate,Shivpuri Extnsn, Delhi 51. We have submitted letter many times since 6 oct 2008 to DDA for fresh demand note of allotment of the flat,which was acknowledged vide reciept no REC/H/08/32638. Dt 06/10/2008. Now DDA deputy director is not listening to us.They are only saying that this nprs scheme 1979 has been closed. DDA is not providing us the file of our case.They are saying we are unable to find your file.,file has been lost. Kindly assist. Regards Kanika Talwar