XPS 15 9550, not starting after BIOS update

Dear Dell, 

I got a Dell XPS 15 9550 through my institution and the laptop wass highly rated. I started the laptop, and after some minutes of using it, it prompted for a BIOS update to be installed. I thought since the laptop was new and I had nothing on it to be disrupted, I might as well get done with all the Windows and other updates and move on with my new laptop life. Unfortunately, after this update, the laptop could no longer start. I tried a bunch of times and some times it would start, other times it would fail. I gave up and sent the laptop in for repair. It wass later returned working fine, albeit with the sound cable disconnected. 

Fast forward to one year later, I got another prompt to update BIOS. at this point I was using the laptop so much and just did not have the time to do updates. I ignored the popup for a really long time, but I do development stuff and any inch of screen on my laptop is valuable. I just could not find a way to turn off the popup so one time when windows took me through a mandatory update that required a restart, I decided to update BIOS as per the popup from Dell was prompting, but after updating, boom!! same problem! the laptop is dead and I need ~30 attempts to get it to start! All I did was follow a Dell prompt to update BIOS and the laptop is now dead. And this laptop is not cheap. I have resorted to my HP Envy which despite being quite aged, is really performing.  

The vendor gave me a number to call, but the few times that I called the number, a lady said she was in another department and that I should wait for her to return to the responsible department. Please advise on how this can be redressed!

Jude