XPS 13 (9333) BIOS updated killed my laptop!

I went through the driver upgrade on the Dell website after recently upgrading to Win10 and the last step was a BIOS update. It did it's thing and then reset never to work again!

I've been told there is no BIOS recovery on this model, however it does respond to the Phoenix BIOS recovery key (hold END then plug in power and power light will flash) but I have no idea how to get it to recover the ROM from USB as per the standard Pheonix recovery on other models.

My questions are

1) can anyone explain this recovery method to me or if they've found another way to revive the laptop

2) since I'm out of warranty will Dell give me any help at all. Surely they can't allow their software to kill their laptop and not be responsible?

Thanks in advance

Stu