Following a satnav without looking out for signs, or seeing them and then ignoring them and continuing with the satnav instructions, gets people a lot of PCNs in London. Satnavs are almost never up-to-date. The GSV view showing the road layout shows the council have gone the extra mile to make it obvious the only turn allowed is to the left. So I cannot see any credible appeal argument for the contravention itself.
There may, however, be a 'technical' appeal based on council mismanagement of the enforcement process. In addition, PCNs can contain errors of content that render them void, although tba, I cannot see any such errors.
So wait a bit to see what the others say, but don't miss the payment or appeal deadline on the PCN.