Was this u turn illegal?

Was stopped by traffic police today on purv Marg for taking a u turn. It was shown by Google maps and oncoming traffic was stopped so I took the turn. But just after 100 mins was stopped by police and fined 500rs for wrong u turn. No u turn sign was not installed on turn and it was shown by maps. Was this illegal or I got unnecessary challan by police? Attaching location in comments