Indigo Airlines – Explotation and overcharging by indigo staff

I had booked an indigo flight 6E275 of 03 Dec 15. My booking reference was WGS5SE on 08 Nov 15 for Rs: 8808 for myself, my husband and my infant child. A day before the date of travel, the Chennai airport was closed and it was informed when we called up customer care that we may either be refunded the amount or the flight will be provided on another day. But both of us belong to Defence forces and my husband had to reach Coimbatore to be able to go for relief operations in Chennai. So we requested Indigo to give us the ticket for the same destination on the same day via Mumbai . But the indigo staff denied to do this. After calling and chatting multiple times they provided us with only ticket till Mumbai and we had to pay Rs 8,754 for onward journey from Mumbai to Coimbatore on the same day by indigo airline 6E363. My booking reference for the same is U6WT5C. I am feeling cheated as despite of travelling on the same day, using the same airline, tickets being available, the airline claiming in their website that they are providing tickets using alternative routes for passengers of flights cancelled by Indigo itself and booking my initial ticket sufficiently in advance, I had to suffer a financial loss of Rs 8,754. I request you to intervene so that Indigo airline does not involve in unfair business practices like this in future and if possible refund this financial loss incurred to me due to unfair practice by the airline staff. Natural calamities and passenger despair should not be used by private carriers to make money like the way Indigo has shown in this instance. I hope my grievance will be addressed.