Comment by ayarmots

For an organization enrollment, the part that usually decides the outcome is the support case, and a callback request through developer.apple.com/contact (Membership and Account) tends to get further than the web form because the agent can see the enrollment record and the declined payment attempts on their side. Have the D-U-N-S number and the case ID from the first enrollment attempt ready when they call. Did the payment decline happen on the website flow only, or also when you tried to pay from the Developer app?