I ruined the account by trying to change to a 63 character full ascii set password (must not have liked the special characters) and then no password would work.
So I searched high and low until I found a password reset page for the email account which involved giving an alternative address.
I immediately received a case number from an automated spamcop bot to that alternative address, and nothing since.
Have waited until now because it was the weekend, but it's now business hours in the US and still no response.
If there's a phone number to ring I'm happy to ring it because I'm keen to regain access.