If you haven't paid the renewal fee yet, there's no need to request cancellation, as appointment slots that haven't been paid are not considered valid. The system will automatically invalidate it. Suppose you insist on canceling the unpaid appointment to create a different transaction. You may log in to your account, click Existing Transaction, and click the red Cancel button assigned to that transaction. However, appointment slots that have already been paid can no longer be canceled as the renewal fee is non-refundable. Instead, you can reschedule your appointment date, but you can only do this while securing the appointment.