Indigo Airlines — Ticket cancelled

Address:

Mumbai

Two tickets have been booked with PNR XK3KSP Mumbai to kolkata and PNR KRZT5E Kolkata to mumbai through MMT.
I didnt recieve any intimation of the flight being cancelled.
I just checked now, and it says both the flights have been cancelled by the airline.
If it has been cancelled by the airline shudnt i get the option of rescheduling to another flight on the same days without any extra charges.
Why is the only option available to me is a refund?
So that i take the refund and book new flights at double the rate?
This is how you cheat your customers?
Is this why we book the tickets well in advance? So that you can cancell the flight as per your convenience and i pay for it?
This is unacceptable and pathetic.