Our flight from Berlin to Frankfurt was cancelled today, and we were offered a train voucher, which we accepted and used. Everything seemed fine after that.
However, we were later automatically rebooked onto a flight for tomorrow, even though we are currently already traveling by train.
My question is whether I can cancel the new flight and get a refund, since we already accepted the train replacement. What are my rights in this situation? The reason I am asking is because we had to cancel other pre-booked tourist activities because of the disruption.