There's a difference between the "Learn & Support" page, which includes help articles, how-to videos, and troubleshooting (kb) articles, and the "Support" page that provides customer support contact information. For support contact information, you started in the right place at the DPS Portal (https://publish.adobe.com). Sign in using a Master Admin account and click "Support" on the left rail. If "Support" is dimmed when you sign in, contact your DPS administrator for access.