Whirlpool India — Parts not available within 4 years

I have Purchased refrigerator in 2017, Raised the complaint on 5th Aug . Technician visited and said parts need to be replaced and then service centre said parts are not available, we will replace as per depreciation value.But today is the 10th day.No call and update from Team.
My question is
1.Why Manufacturing date 2017 product parts not available? It is just 4 years
2.Why to confirm on Replacement for depreciation value is taking such long time