In cases where the billing provider is not able to authorize the credit card provided, the account will automatically be locked by the system and access to the Incapsula dashboard will be blocked.
While the account is locked the sites under it will continue to function as usual, and traffic to the site will flow as regularly. If the account is in locked state for 30, it will be deleted from the service and traffic to the sites will be bypassed directly to the hosting server.
Once you will attempt to access the dashboard, the option to re-enter the credit card details will appear, and following it correctly will lead to the account's release from the locking state.
If you have done the mentioned procedure and still get locked, please open a ticket at support.incapsula.com.