GOFIRST AIRLINES - refund of flight booking

I booked a flight ticket from Kochi to Hyderabad.they offered full refund for covid patients.I submitted all documents as instructed. I requested for refund but they credited my refund amount to their credit shell and advised me to use next booking time.Unfortunately they cancelled all the flights to hyderabad sector. then I requested for refund but they refused.Now flights to all the sectors stopped. now also they are refusing ,saying no provision for refund ,saying it was a goodwill gesture they credited amount to credit shell.