Good But Poor Service

I am using a Duster for the last 4 years. They are unable to support after-sales service, they could resolve the AC issue for the last four years in my car and stopped even responding to my AC complaints about the last two seasons, even the MD's office writes to me that my car is fine and I must drive it. The solution they provided is to switch the fresh air mode once the following gets affected. It's a weird reply to a non resolved compliant.