You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
I charged there yesterday, I was there less that 2 hours. Place was very busy with a row of teslas charging and some waiting, managed to get charging in 10 mins, Did not see any signage at all.
They are beside every charger, in this picture you can see them. You could try ringing on 01748 850900 option 7 and see if they can fix it before you get a fine letter. Just explain you missed the sign.