Before the strike, DB had announced on its website that, depending on the traveler's choice, (a) the train commitment for a saver fare ticket was lifted and, if possible, you could travel via another route, (b) any ticket could be canceled and refunded, (c) any ticket could be used at another day with a free choice of train. If you have nevertheless bought a new ticket unnecessarily, you are not entitled to a refund of it. However, you can still claim a refund for your unused ticket, the easiest way to do this is via the Passenger Rights mentioned in the previous posting. I would have no illusions about any further claims.
But it can't hurt to write to DB (with a copy of the old and the new ticket) and describe the case. Perhaps they will refund the additional ticket cost as a gesture of goodwill.