My iphone X camera stopped working, shows a black screen when I open the camera

THanks you Joseph S for your effort to help me. I have previously done all you suggested plus more to fix the camera, Face Id, and Facetime (all functions and Ap that require a camera is not working). These issues stared when I did the last update. Apple has confirmed that it is a hardware issue and I can not fix it. The only way Apple will repair it is if I send them my phone and $600 and they will repair and return to me within 7-10 days.... My phone is less than 1.5 years old (iPhone X) and I am furious at Apple... They should stand behind their products. I paid way to much for this phone for it to not last. It is not my fault the hardware is not working... I have not damaged the phone in any way.. It has not worked correctly and had camera issues ever since I did the update in June. It slowly got worse and now the camera and any function related does not work. I expect more from Apple and I expect a phone that I pay so much for to atleast last until I get it paid for. Apple has abandoned me and I am now stuck with a crappy broken iPhone. I am so disappointed.