Hello @soyin0508
Saver offers are generally neither exchangeable nor refundable. Due to this limited and binding offer, a refund is usually declined. Exceptions are made if there is an identical new purchase. More info here: Ticket refunds | SBB help & contact.
For further information, please contact our Contact Center by calling the number +41 848 44 66 88 (CHF 0.08/Min.) or from abroad +41 51 225 78 00.
Have a nice day.
Kind regards, VlaznimA.
