Cant join Partner program

we want to do the following and need some assistance from you and your team.

1. We want to enroll in the following program https://developers.marketo.com/partner-sandbox/
1. For this I tried to register<companyname as a partner using https://partners.adobe.com/exchangeprogram/experiencecloud/prereg.html

1.      And I followed the Register with an existing Adobe ID under my email name@domain.com
2.      After I fill in the form it says this company exists. How can I add social27 to partner program ?

1. Goals I to get a Partner sandbox enabled asap.