For some events the event organizer allows ticket buyers to cancel a ticket until a set time before an event starts.
To cancel a ticket go to Conferize.com/Mytickets and click "Manage tickets". If the option to cancel a ticket is available here you'll find a button saying "Cancel ticket". Click that and confirm.
Please note, that cancelling a ticket in itself does not entail any refund. Any refund needs to be arranged with the organizer directly. If you have questions about the refund policy for an event, please contact the event organizer directly.