Indigo Airlines — Cancelled my flight even though it was operational

Address:	Mumbai City, Maharashtra, 400093
Website:	www.goindigo.in

I had an indigo connecting flight from chandigarh to delhi and delhi to dibrugarh.

I received the below message:
MS Prostutee Goswami IndiGo flight 6E455 from IXC to DIB on 09Jul17 is cancelled. Reason: Your flight is cancelled due to IndiGo operational reason. Inconvenience is regretted. For assistance call [protected]|[protected]

But to my surprise when I booked a different flight at the same time and reached airport, i could see the flight was operational.
I had to go through so much trouble and shed so many extra amount because of this inconvinience.
How unprofessional!! They should be penalised for the trouble caused.
PFA, the photo of the board which displayes that the flight is operational for the same day.