warranty

Hello, I've purchased iPhone 7 plus 12.2016, from Apple Store in Canada. In 11.2018 after the last upload my iPhone is turned off automatically without any damage, I've been home to some technicians who were connected to diagnosis service on pc, they said there's something wrong with the iPhone from the factory. It was very sad and difficult for me because I had all type of iPhone 4.5.6.7 plus the iPhone 7 plus. I'm offline now. I have bought it for $ 970, so I can not afford to buy new, I ask you to help me repair my mobile phone, if you can not help me with the warranty. Or switch to iPhone X so I can pay intermediate money for it.

best regards

Niaz