Spice Jet Airlines — Not refunding money from credit shell

I have booked ticket with spicejet frkm patna to hyderabad and the flight was cancelled due to lockdown.They put my money in credit shell with validity march 2021.Now as per the government order they have to refund the credit shell amoumt but I have written so many mails they are not replying.Also the customer care executive is sayi g they will not refund money and have extended the validity to next year.Also tney are deducting vonvenience charges of 500 from the total amount whereas indigo has refunded the total amoumt uaed to book the flight.
I want the refund of my credit shell and spicejet is not taking any action.