If you purchased your The Tapping Solution App subscription through the mobile app via iTunes, you will need to contact them directly in order to request a refund. Only Apple Support can process refunds for purchases made through an iTunes account.
Please contact Apple iTunes Customer Support directly at https://support.apple.com/contact.
We also recommend that you cancel your subscription to avoid being charged again next billing cycle. To do so, you would need to turn off the auto-renew within your iTunes account settings.