When the guest is ready to leave the event, they can visit an employee who is approved to “closeout” wristbands to have their wristband deactivated.  The employee can then optionally refund the wristband’s remaining balance (or some portion of it).
After the wristband has been closed out, it can no longer be used for purchases or top-ups, preventing a guest from continuing to make purchases after receiving a closeout refund.