I HAVE LOST THE CARD
You can temporarily block your card either through the Santander App or via Online Banking. To do so, just access the card and turn it off.
When you need to unblock it, activate it again by switching it to ON mode. Then you can continue using it without any problem.
In case you can't find your card, request its total block and get a new one sent to your address. You can perform this operation via the Santander App, Online Banking or by calling 900 811 381.