@highspiritz I'm not sure much of the above discussion is useful, here's a draft representation for you:
Dear London Borough of Bromley,
I challenge liability on the ground that the alleged contravention did not occur. This is because the signage is inadequate, I refer you in particular to paragraph 13.2.9 of Chapter 3 of the Traffic Signs Manual which states that "Where the bus stop marking has been extended to accommodate two or more buses, it might be preferable to mount the sign close to the beginning of the bay. In these circumstances an additional sign, mounted parallel to the kerb, might be required near the centre of the bay."
On this occasion there is only one sign at the far end of the bus stop and the driver could not possibly have seen it, it follows that the signage is inadequate and for that reason there was no contravention.
Yours faithfully,
Send this online via https://parking.bromley.gov.uk/live-3sc-user/ and take a screenshot of the confirmation page.