Happy Easy Go. Com - Flight ticked amount not refunded

I booked an Indigo Jaipur to Bangalore flight on *th March **** with travel date **th March **** along with an option to reschedule it for free in case my travel plan changes. I would just need to pay fare difference and airline cancellation fee will not be applicable. On **th march my plan changed and i requested Happy easy go customer support to re-schedule my flight. The sent me the revised amount payable which included both airline cancellation fee and fare difference. I kept following up with them entire day over mails and calls to revoke the cancellation charges and just levy fare difference but they were asking me to pay cancellation charges in the name of fare difference . I even made a conference call with Indigo with them to explain them this included cancellation charges. Due to delay in response i couldn't reschedule the flight and had loss of entire ticket amount. I have a detailed email conversation with their customer support that i can forward you as well. attaching the ticket for you reference.