If you need to update your credit card details or manage your subscriptions you can do that from the Appexchange directly.

• Login to the Appexchange with your Salesforce credentials.
• Navigate to “My Installs & Subscriptions”
• Locate the RIO Inventory App,  from there you can use the down arrow to Manage Subscription.
• Click on Edit.
• Update the number of Users you need – any charges for additional Users will be pro-rated to match your current subscription period.