Maruti Suzuki India — dzire zdi

I purchased one maruti dzire car (Zdi) in 2013 june through indus motors kesavadasapuram, pattom thiruvananthapuram.
The agent was aneesh nilamel, kadakkal.
I have done all services in time at indus, hercules, etc. Authorised service stations, and no any other workshops attended any repair/replacement other than those authorized ones.
My complaint is that the front wind shield (Front glass) developed scratches, after two years of purchase and became difficult in driving night time.
I approached several authorized points but they could not rectify it.
Finally it is said that this company made original glass is to be replaced with another one, but in the cost of insurance and a part payment from me also.
I am complaining on this issue because, is it a clear manufacturing defect of a part of the vehicle?
My car reg. No. Is kl21g/7855.