As it's a TfL PCN, you can only look at the video by phoning them up and asking for it. They then freeze enforcement for 10 days (approx), and send you a DVD. Yes, TfL are in the IT Dark Ages ! If you haven't received it in 10 days ring them up again.
Here is your No Right Turn location. just after a bend and poorly signed in my opinion.
Find local businesses, view maps and get driving directions in Google Maps.
They obviously know it's not much good, because they've painted "Ahead Only" on the carriageway which with London Traffic you're almost never going to see. A single sign that is likely to often be obscured by high-sided vehicles. Buy Hey Ho, it gets them their money, so improvements are very unlikely.
Were you following satnav instructions ?