Indian Railway Catering & Tourism Corporation [IRCTC] — Non refund of Amount

I booked flight ticket travelling from jammu to srinagar but my flight is cancelled due to covid-19. Airline suggested and offered a credit shell voucher for future journey. When i was trying to book ticket from credit shell it is not book than i contacted to irctc because irctc deducted the booking charge and i booked ticket from irctc. Now i want my ticket amount back and i m not interested in credit shell facility and i m not going to travel in future upto 2021 it is my decision. So i m requested for refund than irctc said “we acknowledge the receipt of your email and would like to inform you that airline have protected your pnr amount in the form of a credit shell. You can use it to make a future booking within 1 year of its issuance, for the same passenger (S). You are not eligible for a refund as the booking/travel date criteria does not match” i don’t want to travel so why airline is not refunded my amount. Who give him right to set criteria of my booking. This is illegal. And my credit shell is also not valid there is error in that. I want my money back.