Free Traffic Legal Advice

I received a PCN for the same 'offence'. I have been going the same route to visit friends for years and this took me by surprise. It is not at all clear when travelling along Rosendale Road in Northbound direction that access to Eastmearn Road via a left turn is now prohibited. You can only see the signs when you make the turn, at which point you have drivers behind you and feel as though you have to go through and complete the turn. I realised this at the time (after seeing plant boxes) but was hoping that the system had not yet been switched on. Surely there should be some advanced warning signs on Rosendale Road to give notice of the new measures. Also, no consideration is made for non-robotic drivers who are not following a sat nav at all times! If you have travelled this route many times you do not expect a sudden change.
In my case, it occurred on 06/10, PCN was issued on 21/10, 50% 'discount'(£65) until 15/11 and then rise to £130.