Meta headset stuck on black screen with white dot in the middle

Looks like you've tried everything. I think your headset may be unusable, There are no Meta staff here unfortunately, no Meta moderators or community managers, they don't monitor this forum, we are all just users here so we cannot help with warranty returns etc. 

However, here is a link to various methods of contacting Meta official support. Hopefully one of them will be able to help. Good luck. 

https://www.meta.com/en-gb/help/support/?g1=5960237440706837&g2=5599442656832658&g3=5947917498632978&et=none&sg=skip