How about the shareholders in the company? The stock should be canceled and the company recapitalized before a single penny is lost by the shareholders. By not paying the account holders the bank has admitted they are bankrupt. (that is assuming they are privately owned. Kind of hard to go officially bankrupt if you are owned by the government.)
The bank’s bonds are guaranteed by the ECB, so you know they won’t be giving themselves a haircut.
This too big/important to fail meme is failure itself.