The one time my bank (wrongly but understandably) blocked my card, they did call me. They said they blocked my card as a precaution, and to call the fraud department at the number on their website.

At the time that was really annoying, but probably also the only right way to do it. It’s pretty weird to answer the phone and have someone say “you need to call us, because you can’t trust that I’m not trying to trick you”.