Jet Airways are Cheating on their Customer

This is regarding a poor experience I had while booked a flight with Jet Airways on 15th Feb 2017. Flight Number "9W 730" dated 15th Feb 2017 was supposed to take off at 14:50 from Terminal 3 (IGIA, New Delhi) and all the passenger were supposed to check in 45 minutes before the flight timings. My wife booked a confirmed ticket for the same having PNR- DONSWY with eTicket # 589 21 2711 1612, reached the Airport at 1:55 which is 55 minutes prior to take off. While standing in the check in queue behind 37 people ahead of her, she asked one of the Jet Air staff that she may get late on which their reply was to follow the queue. When she reached the check in desk at 2:20, she was told that flight was full and has already been departed.
Story doesn't end here, she requested to arrange something as she was travelling on a family medical emergency, however couple of Jet Airways officials were rude and denied to help. When She tried contacting the help desk, they mentioned there is no flight for the day and there is no room available even on 16th. When She asked for the refund, she was told only 1500 INR will be refunded.

I called customer care team and got to know that Airport staff has punched our check in time at 02:38 PM which is not at all true. We reached at 1:55 and informed the officials where they suggested to stay in queue and we got our turn at 2:20 where we were told that boarding gate has been closed. No one has even checked the time at the time of boarding but when she was coming out of the Airport, she was told to contact Jet Airways customer center where they did something on their system and might have captured the exit timing. After talking to Manoj Kumar (Floor Lead) and Sindhu Sharma (Manager-Ops), I know the intention how you guys are doing business and can't help me with the resolution.

So here I am expecting a highest escalation email before I go legal as that will require more information and time. Also, wanted to know under which jurisdiction, I can file a complaint against Jet Airways? I checked but just wanted to confirm before I hand over this case to my layer. Also, thinking of spreading this news across all the social networking sites to make people aware how you're doing business.

Now here is my question:

1. How come flight took off before the scheduled time and seat which we booked was allotted to some one else and we kept standing in the Queue.
2. I booked another flight, with flight number- G8 - 217 and PNR- HICD8U for 12,373 INR, at 19:08 where I paid more amount and got late too, who will be responsible for this?
3. Why the staff denied to refund the 100% of the amount which we have paid even when we were on time?
4. How dare Jet Airways staff sounded rude to us as we are taking service by paying a price not taking any charity from you guys?
5. How come they claimed that we reached the boarding gate at 02:38 when no one has even checked the ticket, but captured the time when coming out of the Airport.

Expecting a resolution before I take this further for legal desk and consumer forum. I hope Jet Airways will understand the severity and take it as a feedback. Also, I can go to court to take out the CCTV footage to ensure were we on time or not.