Sorry to hear about this Steve. I can imagine you were quite scared at the time, I know I would be if a group of youths, or even kids, attacked me. I doesn't matter how old, big or strong you are, if a large enough group of kids attack you there is little you can do to fully defend yourself.
I also hope that can catch them, although I very much doubt the Police would be able to do that much if they did catch them. Most are let off with cautions, or bailed to appear at the magistrates and then never turn up so break their bail agreement and nothing much is done about it.
Personally I thing the eye for an eye philosophy should be used for such people. They should be chased and pushed to the ground and then kicked and punched a few time. Although I would love to see stocks reintroduced, and possibly bring back public stonings for the really worthless wastes of space!