I am afraid that these situations are only dealt with by persistence, you have to be more persistent than your anti-social neighbour and the council. Firstly, I suggest that you have to become the proverbial stone in the shoe of the council. Got to every single relevant council meeting (Parish, District and County) (or unitary authority) and raise the issue that a hedge has been destroyed and that untaxed vehicles are being parked, what are they doing about protecting the green belt etc, and take some of the other thirty with you. Back your verbal protests in writing and find out who your local paper reporters are an keep feeding them with relevant stories -( most of them come the end of preparation for publication are scrabbling round for stories!I I must say my experience is that people say they are right behind you, but leave you wondering how far behind! Get your binoculars out!
As I said it is a lonely road, and you have to decide if the aggro is worth it, but if you don't make a stand where does it end - two vans, three, gypsy encampment.....?
Make sure you know your local structure plan and what is intended for the development of the area and the planning policies of the council - there are usually some things that are arguable (eg This in contravention of Council policy SG16 or whatever of the development plan - you'll find something!)
Good luck