MakeMyTrip India — Flight not operational Refund not processed

Regarding this flight on 5th of May (Ahmedabad to Delhi)
Make my trip is sending me an email with this details

Kindly help me for the following issue resolving it's been more than 20days i haven't got any refund amount

The refund process has been delayed.
Once the airline approves your claim, we will process your refund.
Your refund application for GC5D3N sent to Go first is still pending approval.
Once they process the refund, it will be auto-credited to your account and a notification will be sent. No telephonic/ e-mail follow-up is required. We appreciate your patience. Last updated: 18 May