Here's the update - after a rather strong email followup, I got calls from some mid-management types in Indigo customer service (Gurgaon), and they are proposing to offer a pitiful Rs. 1K in travel voucher. I was told that's the max she could do, and that there is no provision to compensate directly with money. They are quite apologetic, but despite my best efforts that individual just wouldn't use the word 'compensation', instead sticking to the more legally neutral word 'good will token'. Their offer is such a joke, think I should just decline it.