Happyeasygo Free Cancellation Fraud

I had booked my flight and opted for free cancellation by paying extra in the happyeasygo application.Later I cancelled the flight and enquired about my refund status from customer care.Then customer care confirmed that I will be eligible for 80% of booking amount after all charges but it will take 45-90 days.Then after 90 days I asked them the status they said you have not opted for free cancellation so only 20% of ticket price will be refunded.then they are responding the same again and again..