Free Traffic Legal Advice

Hi everyone, hope you all doing good. I have been issued a speeding ticket- doing 47mph at 40mph limit, received NIP to send them details of the driver. I can’t upload the pics on here but when I looked at photographic evidence on first pic it says my speed is 47mph while my car is imaged from a distance and other car partially comes into the pic as well but green dot pointed at my plate number. Second image is zoomed in at my number plate but on the pic it says speed of 29mph. I’m not sure if I was speeding as it’s a 50mph road and only for like 200meters they reduced it to 40mph. I don’t have dashcam to look back at my speed or anything but both pictures have confused me and I’m just wondering if I have been issued the NIP wrongly when may other car in the pic was speeding not me. What’s the best way to find out? I wish I could upload pics on here. Thanks in advance.