Hallo hyo,
We will look into this matter and refund if applicable.
Please complete the refund form and send it together with the additionally purchased tickets:
https://sbb-tickets.cc/en/travelcards-and-tickets/buying-options/formular-erstattungsantrag.html
For tickets obtained at the station or by post please print out your refund request (PDF document) on that website and send it to us by post:
SBB Contact Center
Refunds rail.ch
Spitalweg 19
CH-3902 Brig-Glis
Conditions:
https://sbb-tickets.cc/en/travelcards-and-tickets/buying-options/online/general-terms-and-conditions.html
Generally speaking, Online/Mobile Tickets may not be modified, exchanged or refunded.
Have a nice day
SamanthaAd