Very over-grown footpath

We set out on the circular walk from Upton Dyke (right hand side), continued along the River Bure towards Acle and then turned off somewhere near Fishley Hall to return to Upton. The last part of the walk leading back to the point where we had started, and marked on the map, was extremely overgrown with stinging nettles, brambles and other unpleasant growth. The path became difficult to follow in places and the experience turned what had been a very pleasant experience for more than three quarters of the way into a dangerous and bruising nightmare. I rang the Broads Authority today but they say that it is not now their responsibility, though the footpath signs have 'Broads Authority' on them.