Airtel — Pending Refund of amount

I was having airtel plan as below
Advance Rental Plan for your Airtel Xstream Fiber ID[protected]_mh is auto-renewed on 13-MAR-21.

Your plan details are:
Plan rental: Rs. 799 /month
ARP amount: Rs 2397
Duration : 3 months
Start date: 13-MAR-21
End Date: 12-JUN-21

I have paid the bill of Rs 2397 in the month of March’21.
Later, on 23 Apr’21 I have requested for closure of my connection as I moved to my native place during pandemic and was not using the Internet. My request was placed with the Airtel team and they confirmed that I will receive my refund amount within 30 days or so.
I have been raising request for my refund on their customer support email ID [protected]@in.airtel.com, but no response received. I have also contacted their customer care and they just informed they can’t to anything we have to drop an email to [protected]@in.airtel.com
I want my refund, this quiet repetitive issue with Airtel