The majority of bookings are made through Online Travel Agencies (OTAs). These OTAs charge the passenger and issue the invoice. They are also the Merchant-of-Record and have access to banking details for refunds.
Some of the leading OTAs include Kiwi, GoVoyages, and eDreams.
If you need to inquire about a refund already processed by CitizenPlane (all refunds are processed automatically), please check your inbox for the confirmation email or look for the charge on your credit card and contact the OTA directly for further information.