Thank you for your question.
There is no refund for half-Fare travelcards for the Covid-19 pandemic. If you are not using your travelcard, you can cancel it. The delay to do so is 30 days before renewal. If your abonnement renews on May 5th, you still have a couple of months to decide. Either cancel it, on April 4th at the latest, so it will not renew, or pay the bill by May 4th to enjoy one more year of subscription.
The cancellation can be done online on swisspass.ch, per telephone at our SBB Contact Center (0848 44 66 88 - CHF 0.08/min), per mail at firstname.lastname@example.org or at a SBB Ticket counter.
Kind regards and happy New Year