I'm sorry, fB. Laws are different in our different parts of the world, but if it had happened here, to a child of mine, some of the things that my husband would do would be to sue not just the nightclub, but also to file personal suits against the owner, the manager who was on duty, the bartender, the bouncer, and any other staff that might have been on hand that night. He maybe wouldn't be able to get them all into court, but it wakes people up to think that they might be held accountable for things that happen when they're on the scene. It doesn't cost that much to have your attorney send a threatening letter, if nothing else. It's also not too hard to convince health and building and liquor license inspectors to pay a few visits, and to have your attorney send a letter the nightclub's insurer. Is there a landlord? You can go after a landlord, here.    And while he was pursuing these options, he would also be very quietly trying to find out the identity of the sociopaths responsible, their addresses and where they work and what they drive, and some time later, after the incident was presumed forgotten, those thugs would probably wind up in the hospital themselves.   

Are you allowed to carry mace, in England? My two daughters and I carry mace and/or pepper spray. There's also a gizmo that you can carry on a keychain that sounds like a siren when triggered. Anything to give you a headstart, running.