If your School has allowed instant booking cancellations you can do this from the 'Activities & Clubs' tab or by clicking into the activities directly from the available bookings section of the home screen.
Once you are in the activity container for your booking, simply scroll down to locate your booking. You will see 'booked' and a trash can icon to the right of the booking.
Click the trash can and you will be presented with the option to proceed and cancel the booking or to cancel the request and keep the booking.
Upon selecting "Cancel Booking", a confirmation message will appear. If the School have chosen the option to automatically refund any payments made, the reimbursement value will be shown and the funds will be transferred to your Wallet (Credit or Voucher Wallet depending on the original payment method used).