Hitachi / Ac — complaint not attended properly

Address:

East Delhi, Delhi

I have Hitachi window A.C. 1.5T (RAT318 HRD). I have purchased that A.C on dated 14 April 2011. I have faced a problem of no cooling and lodged a complaint for the same on 19 march 2012. Technicians have visited and said to me that there is a leakage of gas and they took the A.C to the service centre for repairing and delivered it back after one week.
Now after one month the warranty of my product is expired and the problem is still persisting and the Hitachi service centre is demanding the payment for servicing the product, but actually my product's complaint was not attended properly because the problem is still same.
so i request pls solve my problem.
Thanks
Rajender Kumar
[protected]
Hitachi 1.5T
110A32263