In general, the exchange and refund before departure is possible with the standard offers. However, you can click on the information sign at the offer overview or details to get more info about the offer. For advice, you can reach the Contact Center at +41 848 44 66 88 (CHF 0.08/min.) or from abroad +41 51 225 78 00.
Have a nice day.
Kind regards, VlaznimA.