Delhi Police — delhi traffic police over speed challan

I have been issued 6 challan by delhi traffic police for over speed compounding rs. 400/- per challan (Total 2400) (Vehicle no. Hr26dc4678) on 31st july 2019 and two in august 2019 on 5th and 26th at carriageway from akshardham to sarai kale khan near just before yamuna bridge towards ring road and carriageway from sarai kale khan to akshardham near just after yamuna bridge towards akhshardham

But as per picture captured by the camera, i was driving at the speed of 60 to 70 kmph. Whereas, the display boards on the same road shows speed limit of car as 70 kmph.

The concerned authority may kindly look into the matter and justify my e-challan/notice and withdraw it.

Regards
Akshath grover