Apple iphone x - faulty iphone x with face id not working

I had bought an iPhone x on **/**/**** from poorvika mobiles Pheonix mall now after using it carefully for all these days suddenly from last two days the phone's face id, proximity sensor, and light sensor are not working the phone is not physically damaged or liquid damaged... after going through some news about this iPhone x I found out that many other iPhone x users have faced the same problem, I called apple support for their help but it was of no use when I visited the store they said me that they need to replace the motherboard completely without even opening the phone, and the price which they wanted for repair is **,*** it seems I am totally down from last *days not able to digest the fraud which apple did to me after having so much trust on the company
my phone is used approx **days more than the warranty period so I am not even able to claim the warranty now.