Easemytrip.com - Credit shell amount can t be accessed

Due to covid-**, my flight has been cancelled by the airport authority and a credit shell has been created. They claimed to return the whole amount, but I received less than the booked amount. Easemytrip is denying about this loss. They are saying credit is created by Indigo airlines and they don't know anything regarding this. But Indigo returns the whole amount along with the convenience fee. After re-booking another flight using that credit shell some amount was left in that shell. But now when I am trying to access that amount to book another flight with the same passenger name and email-id, I am unable to access it. Why is it happening? How can I get the balanced amount back?