refreshed admin email, locked out of 365 account - "doesn't exist"

I subscribed to trial 365 and was messing around. It asked me to enter a new email, I assume, to replace the long **bleep** one with the ugly addition on the end (can you tell I am a noob?)

When I enter any variation of the email, or even the original one, to access the admin centre "it doesn't exist" and right this moment I'm trapped with a subscription that I cannot even cancel.