I just purchased the update from 8.5, but recieved no invoice or any kind of conformation email about the purchase whatsoever.
Also on myproducts on steinberg page, there is no cubase 9 listed. 
I’ve tried to send an email to steinberg support but failed miserably to even find their email address anywhere. 
From the impression i got today, dealing with any kind of major issue for the first time, and trying to find a way to talk to the support, i wouldn’t be too surprised if my 100 euros will go to waste
Please help. 