For anyone who is still following this topic!
The Council issued 5 remedial notices over a 3 year period, most of these were found to be defective and subsequently withdrawn a few months later only to be replaced by another one equally defective. Eventually the Council took me to court, I engaged a solicitor, they then withdrew their charges and reimbursed my £4000 legal fees, and also paid their own fees which amounted to another £4000. So, all these years later, the hedge still stands, and an irresponsible Council has squandered £8000 in legal costs, plus the costs of their own internal administration which theoretically could be another £5000. During the course of this process I wrote 50+ letters to the Council including several to their Chief Executive who did respond but failed to address the issues, if he had of done, the Council would have saved at least £8000. My advice is to put everything in writing, no emails, no meetings, and no telephone conversations, log absolutely everything you do in a diary, log how long it takes the Council to respond to your correspondence (a proper response, not just the acknowledgement postcard!), always raise a complaint with the Council if you are not satisfied, and don't ever give up or show any signs of weakness. As a typical working person, I'm definitely not in a position to sustain costs such as these however, continually and consistently chipping away at the authority when I disagreed with their assessment eventually paid off. Good Luck to anyone else faced with something similar.