iPhone stuck on Low Battery Screen

Hi All,

Since Monday afternoon, my iPhone XS has been stuck on the "Low Battery Screen". I have charged it for the better part of two days without change.

Yesterday, I took it to the Apple store, where the Genius ran tests and said that basically nothing appeared wrong and that if left alone, it would eventually turn on.

Having left it to charge, Since then, I've seen the display change briefly to the Apple logo followed by a blank screen. On a couple of those occasions, I've managed to get it to the restore phone screen, prompting me to go to this website: https://support.apple.com/en-us/HT203122.

After following the reset instructions on the website, with the phone still plugged in, rather than restarting, it goes back to the empty battery screen.

I'm wondering if there's anything I can do to get past this? Or is the phone shot?

Many thanks,

Peter