Looking for help from anyone who has encountered the same situation on the same airline.

Involuntary schedule change on Indigo Airlines. New time is inconvenient. I want to switch to a more convenient flight same date/different time. All pretty standard. However, Indigo refers me to their 'edit booking' function on their site where they want to charge c.6000 rupees to make the change. On every other occasion when this happens on any other airline I fly on, this is free. I've asked on Indigo's messenger page and am directed to same place on their site.