Let me put it this way, their memory means nothing. Eventually they lose all claim on it. Not quickly, but it does happen. Their error, she tried to fix, they don’t, she tries again, they don’t, they’re rapidly running out of options. They can “remember” all they want, but it’s still their mistake, and she tried. You don’t want to go quick because there is a time period when the law will favor them, but eventually it’s too bad for the bank.
Looking over the different responses it struck me how all of us seem to answer the issue from a pragmatic viewpoint rather than a moral one including yours truly.
Bottom line is: DON'T TAKE WHAT AINT YOURS!