Indigo Airlines — refund of flight

I arrived at the boarding 3 mins late than the stipulated 25 mins window (I. E. 28 mins). I'd simultaneously (That very moment) received a call from an indigo rep asking me where i was. Shockingly, the lady at the boarding gate said that the gates are closed and i have to book another flight. As the other rep was already on call with me i told her to speak to her. But the lady the gate counter refused to the person on phone and i was compelled to make another booking.

As the indigo rep had called and she said she was waiting at the very time i was at the gate, i'm sure something could have been done about it. I have been travelling for years and have seen passengers enter the gate way after the 25-minute window. But it seemed like indigo has this new strict way (Of possibly earning money) as there were many people who were given the same treatment. There was apparently an indigo rep standing right at the security who was telling people that the gates have been closed.

Due to the excess queues at airports these days and mismanaged operations, anyone could be late by a minute or two. But the airline isn't cooperating at any circumstance.