Unfortunately TfL aren't going to do the OP's legwork for them and 'As can be seen from your photographic evidence, my vehicle was not in Fairfield Road SW16 at the time of the alleged contravention.' without any evidence in support wouldn't get them to do more than look at the PCN which doesn't show where the alleged contravention occurred and therefore they'd act on the PCN location.
OP, IMO ask for the video. Progression would be put on hold following receipt.
IMO, and this appears to be confirmed by the OP's post the 'photo was taken from the London road network camera'. My guess is in the loading bay just along from the Chicken Cottage, 1426 London Road.
Whereas the embedded photo appears to show only a parking exempt area, the colour photo shows a second sign behind this which would govern the loading bay and also shows 'loading only' road markings.