Their refund policy states: Ticket details Paris Gare de Lyon to Marseille St-Charles, Wed 19 Oct 2022 BUSINESS PREMIERE Exchange and refund free of charge up to 30 minutes after departure. From 30 minutes prior to departure, tickets can be exchanged up to two times (for the same day and the same journey), and are non-refundable after the first exchange. To take a different train, it must be exchanged. Guess what when you cancel they do not refund the entire trip cost... they keep a transaction fee that is not disclosed and that is called fraud... so if you have to cancel beware.