Not yet. Nothing is charged until payment completes.
No payment is taken until you complete the Stripe payment page, so if you clicked away or cancelled, you haven't been charged.
Your pitch stays reserved for about 10 minutes, so if you head back quickly you can finish paying. After that the reservation expires and the pitch is released, and you can start the booking again whenever you're ready.
Email support@pillowcase.io with your campsite name or booking reference and we'll pick it up from there.