I went through the first of 2 no entry signs on queen victoria street, as you approach Bank junction, which I didn't see. Subsequently turned around about 10m down the road when spotting the 2nd sign (which I didn't go through). There is video evidence on the online portal that has me banged to rights going through the first sign.

However, on the letter they sent (see link below), the picture shown is totally unrecognisable. Do I have any chance to appeal this based on the argument that the evidence in the letter sent is not recognisable or indicative of any offence having been committed?

Letter Received:

Many thanks in advance for any advice

Street view on google maps does not show the up to date signage.
The location of the alleged offence is: 51.51315 -0.09085