So here: https://maps.app.goo.gl/1DwJgjcDBt9zFY8L8
The traffic order is The London Borough of Hounslow (School Streets) Order 2021 (https://store.traffweb.app/hounslow/documents/parkmap/sched/2021-56.pdf).
If you'd come from here https://maps.app.goo.gl/jTDNMQPy6cDn4JCh9 I don't see how the signage could be adequate.
Frankly I'd just make a very simple representation:
Dear London Borough of Hounslow,
I challenge liability on the ground that the alleged contravention did not occur, if you maintain there was a contravention please would you provide evidence of the same.
Yours faithfully,
As long as this is sent during the initial discount period, if the council rejects it will almost certainly reoffer the discount anyway, and we might get some meaningful insight of what video evidence there is. Keep a screenshot of the confirmation page once submitted.