Hello Sunyou
The ticket refund must be made before train departure. We are obliged to adhere to these conditions as we cannot claim any amounts back from our partner railway companies once this deadline has expired.
For future international refund requests, please choose the telephone contact (telephone number: +41 (0) 848 44 66 88, CHF 0.08/min. or +4151 225 78 00 from Korea, available daily during 24h).
For more information on exchanging and refunding international tickets, visit sbb.ch/en/refund.
I wish you an excellent day.
Kind regards, RahelW