Apple India — Phone dead within 1.5year

Address: Mumbai City, Maharashtra, 400022

I got two iphones 1) iphone 6s 64 gb rose gold
2) iphone 6 64 gb space grey
Both the phones got dead in consecutive months with 1.5 years from the purchase date (Motherboard issue they say)
Now the apple authorised service centres is asking to replace the phones
Costing 25 thousand rupees each
What is the customer benefit if he is paying this much money, double the amount. This is not done
We look at apple with trust and belief
But this is completely fraud