Apple iPhone X 64 GB Battery Problem

On April of 2018, I have purchased iPhone X 64 GB from the United States. Recently, I started to have a problem with the phone's battery.

So, I immediately called the Apple customer service, and when I called the Apple turkey service, the customer service representative told me that "Process saying it was invalid in Turkey guarantee my phone they said they could not."

I think this problem is a very bad image for a company like Apple.