I just tried this on my test account (which also does not have a pin) and am able to submit a support request.
1) Go to the following URL, substituting DOMAIN.COM with your actual domain name: https://www.google.com/a/
2) enter a secondary email.
5) contact Google Support if support link is not shown here then go to steps below.
Alternatively you may get a couple additional steps
5) Reset your administrator password by domain verification
7) contact Google Support
In the description make sure and state that you cannot access the control panel for your domain and that you have no users or admin accounts for your domain. Don't forget to tell Google Apps team your domain name.
Please note this support access is for those who can not access control panels only. and is not for other support cases for other support case types you need the business edition for support access.
Advisor Ricky Post here