Please note that only the account Owner has access to Billing and Invoices and can modify the Subscription.
As the account Owner, you can increase or decrease the number of connections from your OpenVPN Cloud Account Portal.
Log in to your OpenVPN Cloud Account, go to your Profile drop-down list. Click your subscription account ("see image below").
Go to the My Plan tab.
From there you can increase and decrease the number of connections you require and click the update button.
You will then be redirected to the checkout page where you can choose to pay via card or Paypal.
When you scale connections up or down, the system automatically calculates the remaining value of the subscription and provides that as a credit (the remaining value of the subscription is calculated on a daily basis). A new invoice is generated using the cost per connection based on your usage and the credits are then applied. After the credits are applied, anything remaining is requested as payment.