We can check into that - make sure that you sign into FormsCentral with the same "AdobeID" (Email address) you used to purchase FormsCentrtal.
You can sign into this page to view and manage your subscriptions: https://www.adobe.com/account/my-products-services.html#MyServicesHeader
See what it says there.
Is the email address you used to sign into this Forum the same that you purchased your FormsCentral Plus subscription with?
We do see that the email you used to sign into the forum does have the Plus level subscription.
Are you accessing FormsCentral from a web browser or the Desktop application included with Acrobat Professional XI? If you are using the desktop application try siging into formscentral.com in a web browser. If you were in a browser try signing out and back in just to be sure you are signing in with the same email address.
What type of new form did you try, new from Template, Custom or import PDF?
You can send me an email to firstname.lastname@example.org or respond further here.