Sony VAIO Laptop, Netbook — laptop exchanged during windows reinstallation

Address:

Chandigarh, Chandigarh

i purchased a sony vaio netbook from tech terminal 2, sect 20, chandigarh on 16th feb 2011...wen i started using d laptop at home the same day, i realised that keyboard was not functional...i took it back to the dealer and he stated there must be some problem with the windows..he reinstalled the windows and gave me the laptop back next day..after 1week, i realised that everytime i used to switch it on , it would go the vaio rescue mode first..after 3-4 days, it stopped functioning, dint switch on either...i again went to the dealer, who assured me thaat it was a problem of windows getting corrupted with virus and again reinstalled the windows and returned me the set next day...
third time again the laptop crashed in 1week, stating operating system not found on screen..this time i went to the service centre and was astonished to know that my laptop is not the same set as i purchased since the serial numbers dint match..the service centre dint accept the service coupon...problem in the hard disc was found...when the dealer was informed of this exchange in set during windows reinstallation with a defective piece, he refused to accept the responsibility...now i am left with a huge mental torture o[censored]sing a defective exchanged laptop, which might again crash anytime, with dealer not helping me out...

Kindly look into the matter and help me out...