Hello HappyOtter
As I understand it, I can get a refund for the Supersaver ticket (subtracting the admin. fee of 10 CHF) if I buy a standard tariff ticket for the same route and date and passenger and I enter the new ticket ID in the refund request.
Yes, correct. You have to purchase the new regular ticket first, then you can request a refund.
It was not obvious from your inital question; there you said, you are unable to use it, not about a repurchase.
Kind regards,
Roland