BIOS upgrade total failure

i have a Dell Venue 8 pro. Today I received a message from Dell that I needed an urgent BIOS upgrade. I recently upgraded to Windows 10. Halfway through the upgrade the battery went dead. Now the battery will not even charge. I can not turn the unit on. Do I need to send the unit back to Dell for repairs. If so, what is the address? The tablet is only a year and a month old.