Also I unable to make an informal representation. See image attached. Is this a technicality I can use to get out of the PCN ?
https://imgpile.com/p/34sd9VR#BQGHMiz

No, not really, you would seem to have misunderstood the system. With postal PCNs, which are sent to the owner, there is no faciity to submit informal reps, only formal ones. This is because a postal PCN is sent to the owner so acts as a Notice to Owner. Informal challenges are made against paper PCNs served at the roadside to car or driver. The council are wrong saying you have been sent a Notice to Owner, though, but it's an easy mistake to make, and a legacy of when, back in the day, all PCNs were served at the roadside
As to the contravention, their video shows you merrily passing two conspicuous No Entry signs, with a plate below stating that buses and cycles are exempt. So you can see how your almost blind faith in your satnav has got you into this mess. The bottom line is that signs are very important and you ignore them at your peril.
Frankly, with the video evidence being what it is, I can't think of a robust appeal argument, sorry to have to say it.