If you've made a purchase and you haven't received an invoice by email, you can download it to your computer from the invoice tab found in your Account panel section.
1. Click on your account thumbnail, and then, from the drop-down menu select Invoices
2. Once the invoice page opens up, simply click on the download button next to your invoice of choice and fill in the details in the Billing Address form that will come up.
Note*: The Billing Address form can be filled in the "Billing Info" section, to avoid a pop-up when trying to download the invoice.