Mumbai Traffic Police — Wrongly Charged challan

I had parked my two wheeler at Sardar Vallabhai Patel Rd, Mumbai on 01/01/2023. I was not causing any danger to other vehicles as could be seen in the photograph below.
I have been charged 1500/- but as per the Sec 122/177 MVA. the fine is 500/- accordingly.
1) It is my first fine and as per sec 122/177 MVA penalty it should be Rs 500.00.
2) I have visited nearby Police Chowky and Traffic police office. No one knows who has imposed fine.
4) Violation is not clear. How can I know what was my mistake so that I can not repeat it again.

With due respect I request you to please verify.

Challan No- MUMCM[protected]XX
Vehicle No - MH01BN2133