Hello Whekonea44
Good day and welcome to the SBB Commuity…
Provided you have purchased the passes with SBB, and not from a reseller, use this form; a cancellation fee of CHF 10 is applied to each cancellation request:
https://sbb-tickets.cc/en/help-and-contact/refunds-compensation/refunds-compensation/refund-form.html?stepId=3.1
If you purchased them as a registered user, what we do recommend, you can cancel it free of charge right in the list of orders.
Before you cancel the ticket, ask yourself if you indeed need another full travel day or if a point-to-point ticket would do as well (and is possibly less costly).
Kind regards,
Roland