Voltas — voltas elegant 1.5 ton A.C not cooling since bought(21-apr-2011)

Address:

Lucknow, Uttar Pradesh

I bought a voltas elegand 1.5 ton A.C on 21-apr-2011from SADANA ELECTRONICS patrakaarpuram gomti nagar lucknow and from the 1 st day i am have some issues...A.C is not cooling , it is making a loud noise and also the compressor start after 10-15 minutes after we start the A.C.
Since the day it was installed I have logged a complaint but no body is trying to resolve the issue , they are just escalating the issue to the higher level and giving us illogical reason about the issue that it is not cooling due to less space.
But the point is that if there was less space ,the person who came to install the machine should have told us the same before installation.
The machine is installed in the window which is opening towards the duct of size 5 feet by 6 feet and open from the top.
There is enough space for heat to get pass from the back side of machine and also the heat can flow through the grill which is at the ceiling.
We daily go to the service center and also to the dealer from where we brought the machine but both try to make us fool and give illogical reasons.
please do the needful to resolve the issue...