You will not receive a PayPal receipt when a merchandise sale goes to Bandcamp to cover your revenue share balance (for more info, see our Getting Paid page).
If you’re using Enhanced Payments, merch orders are processed first by Bandcamp and paid out to your PayPal account 24-48 hours later (for more info, see our Getting Paid page). If you haven't received your payout yet, it may still be on its way. Visit your Payments Summary page for all scheduled payout information, accessible via your Tools page.
If you’re selling physical goods and are used to only looking at PayPal to see who to send orders to, you’ll need to change up your routine a bit. The best approach is to use your Merch Orders page, but you can also rely on the email receipts you get from Bandcamp or export your Sales Report (which is available from your Tools page).