Why would Apple Service not replace a part of my iPhone?

hi...i live in another country, my aunt sent me a iphone, but I think it was opened. there's a lot of dust on my front camera

and i sent it to the nearest apple service but they said they would not replace the part?

they said they won't exchange parts of iphone xs max in my country😓

what can i do?

( sorry for my english)

and my mom thinks i'm kidding but i cant use face id 💀

[Re-Titled by Moderator]