Hello,
I can't answer the question for digitec, but you should be able to do the update yourself.
Does the device not boot at all?
With the newer boards, you can do a firmware update by booting the board directly via a USB stick and the update is automatically installed. This is described on page 27 of the Asus manual. You have to rename the update file and copy it to a FAT32 USB stick, then boot the system with it:
https://dlcdnets.asus.com/pub...

I don't know the ASUS boards, but it is at least with the MSI boards that the update also works this way without a CPU being installed on the board, so exactly the problem you have can be solved this way. It might be worth a try, otherwise I would recommend that you request a return on the digitec site and have the board replaced.