You can access 'Billing' page from 'My Account' menu by clicking it on the right op corner of your panel. You can observe the details of your plan, also check other available options if you wish to switch plans. Click on 'View' to go to invoice details. Here, you can see your invoice, print or download it in PDF format. Please be informed that if your account email address and billing email address is different; the invoices will not be accessible from your panel but they will be sent to your billing e-mail address provided by you.