Thank you for getting in touch. Credit card processing fees are deducted from your Shopify Payments payouts before they are paid out to you, rather than being billed to you at a later date. You can view your payouts and the fees deducted by heading to Settings > Payments in the Shopify admin and clicking on "View payouts". This data cannot be exported as a PDF file but can be exported in CSV format.
Victor | Shopify Social Care