XPS 15 9570 keep suddenly shutting off randomly

My dell XPS 15 9570 keeps suddenly shutting off. It happens at complete random. I will be just working on a word document, without even being connected to the internet, and the laptop just shuts off. It is really frustrating as it is now happening more and more frequently. I have only owned the computer for 1.5 years, but because my warranty has already expired, I cannot get any support from Dell.

 I spent a lot of money for this laptop and now it keeps failing. A lot of other people also seem to be having the same issues too. (https://www.dell.com/community/XPS/XPS-15-9575-2-in-1-going-to-sleep-shutting-down/td-p/7394825)

I have tried all solutions recommended in the thread above. Nothing has worked. My laptop is now a piece of junk. If anyone know how I can file a complain or get support from Dell, please let me know. Thank you.