Indigo Airlines — Non refund of entire ticket amount on account of non operating flight

Address:	Gurgaon, Haryana, 122002
Website:	book.goindigo.in

I have booked a ticket for two passengers on 4th March 2016 for an Indigo flight from Delhi to Bangalore for 24th April 2016 on the official website of Indigo airlines.
Flight number- 6E 643
Departure time- 11:00
After confirmation of the ticket, I tried to book a ticket for 3 more passengers on the same flight but was unable to find the flight details on the website of Indigo airlines.
Later, I tried to book the ticket for the same flight through the website makemytrip.com and found a message stating that the flight numbered 6E 643 is non operational on 24th April 2016. I immediately contacted the customer care of Indigo airlines. The customer executive stated that the flight is not operating on the above mentioned date. When I informed about my booking and asked him to arrange refund of the entire amount paid to my bank account, he asked me to hold for 2 minutes. Later, he informed me that the flight is operating and booking of tickets is closed and advised me to cancel my ticket and try booking for another flight. As per his guidance, I asked him to cancel the ticket. Later, I found out that only Rs.3258 would be refunded out of the total amount of Rs.7608. The customer care executive misguided me regarding this to avoid refund of entire amount.
When I checked with other travel agents and websites, I was informed / found that the above mentioned flight is not operational.
Since they have hosted a non operational flight on their website, causing losses to the customers who booked their tickets, I request you to check into this matter and advise Indigo airlines to refund of my ticket amount i.e., Rs.7608/- at the earliest..