Sorry to hear about this frustration especially as the camera is so new.
I updated mine to the latest firmware - the other evening and all went well.
I agree with the suggestion to try and turn it on while holding down the back button and see if it brings up the firmware update screen and see what it says and if it shows old firmware try again as there may been a glitch.
Failing that it will as suggested require a return to the original seller as there must have been a problem when sold so you are entitled to a refund.
There are some good deals around and tomorrow (Black Fri) some are selling the camera, 18, 27mm and camera case for £499.00 after that they may be back to £614 price so still an amazing deal.
Good luck whichever way you go.