Hello DET99
Have you bought your passes with SBB? If yes, see my instructions below, otherwise you have to contact the point of sale.
Have you bought your passes with SBB?
You can either call SBB at +41 51 225 78 56, 24/7, or request a refund using this form. A 10 CHF admin fee will be deducted. See the request form here:
https://sbb-tickets.cc/en/help-and-contact/refunds-compensation/refunds-compensation/refund-form.html?stepId=1.1
Choose option: Tickets or reservations in Switzerland (without supersaver offers).
No, you do not need to cancel both, just the one containing the erroneous date of birth.
Kind regards,
Roland