Apple India — iphone mic does not work - no resolution provided by apple

My father's iphone 7 had a issue where the microphone of the phone did not work. I had raised multiple cases with apple support. One such case id is[protected]. I had even visited the apple care store, but there was not resoution to the problem. The phone has been take care of very well. It has only been 2 years since purchase and the only issue is with the microphone, and the apple folks are unwilling to help at all
The apple care store just wants to give only 2 resolution to all the issues for which people come to their store for - replace the device. Does this look like a joke that every time something small happens, we are supposed to shell out so much money and replace the device? The only issue is the microphone, which can very easily be replaced, but i do not see any effort being made by the apple support team to even try this solution.

I would like to raise a complaint against apple inc. As well as the apple icare store in elements mall, bengaluru, india for not trying to solve this issue.