Indigo Airlines — ignorance of staff

I had a flight on 31/12/2017 @ 1:20 pm from delhi to coimbatore.
At the boarding counter that lady told me that flight has gone (As i was there 1:08 pm)
I booked another ticket and when i was going to terminal 3 i got a message that your flight is rescheduled.
Why couldn't she told me at that time.
I hope that indigo will look into this.
Thank you
Sayed ale imran