I have the same problem, although it's from a back alley originating in someone's garden further down. I just keep chopping it back and pulling it up, quite satisfying when you get a nice long one that comes off in one :)

I wish I knew, I do spray through the fence with weedkiller but to no real effect. I would be trespassing if I went over my 6ft fence so there is not a lot I can do as the years go by it gets worse. You could of course ask your neighbour if it is possible to dig it out which will reduce it for some years.

Keep pruning it back there is no other way I can think of.