Indigo Airlines - Flight missed due to irrational and unethical attitude

Dear concerned,
I reached the airport ** min before the departure and I was standing in the queue ** min before departure. I was made to stand in the queue (I tried approaching the guy standing at the counter he said request the passengers and come in the queue if they allow) and no final announcement was made. They did not let me board the flight and I had to pay rs. **** extra for boarding the next available flight. The guy doing the booking was non-cooperative and did this on purpose. I think my ticket was sold to someone else.
I am a lawyer and a chartered accountant and an aspiring judge and I very well know my rights. What happened was compeletely unnacceptable and penal. I want my money to be refunded immediately and I want an apology stating that the same would not be repeated again. If the same is not complied with I am sorry to say but I won't be left with any option but to file a legal complaint as I have my receipts and I have my uber trip details when I reached the airport. That would be sufficient proof to go ahead and prove my point.