Hi. I recently ordered a headset from Canada with free shipping and got it today. And I found a commercial invoice in a plastic bag on the parcel. The invoice says something about Invoice subtotal, Freight costs, accessorial costs, and so on. I don't normally see this invoice document when I order from Canada Amazon. Can someone clarify that the cost on the invoice is not something that I have to pay? I paid the product price and local taxes at the checkout. Thanks.