Ask the campsite to cancel. You'll get an email confirming it.
Contact the campsite and ask them to cancel, quoting your booking reference. Cancellation terms are set by each campsite, so check anything they've included in your confirmation email.
Once the campsite cancels, you'll receive an email confirming the cancellation and the reason. If anything looks wrong, contact the campsite straight away.
Email support@pillowcase.io with your campsite name or booking reference and we'll pick it up from there.