Most people think that if they are attacked in public, people will rush to help.
But they don't. And you're not the only one who's found herself in this position, MrsDeVere (link, if interested): www.guardian.co.uk/commentisfree/2013/jun/21/domestic-violence-global-disease-not-powerless
There are complex reasons behind this, not all of which are to do with indifference - sometimes it's uncertainty, sometimes fear, sometimes fear of doing the wrong thing.
But if you're being attacked, any attempt to help NOW is what you want. Anything. Even acknowledgment that you've been seen, and somebody actually cares, is better than the terrifying, lonely experience of trying to fend off assault with no hope of help from anyone.
I think you deserve recognition for what you did, MrsDeVere. You stopped the assault. You made a difference.