Freakins India - Returned the product haven t received any refund

I would like to file a formal complaint against Freakins (online clothing brand) regarding unfair trade practices and wrongful charging during product exchange. I had placed an order under a BOGO (Buy One Get One) sale and paid prepaid. Due to size/exchange issues, I placed an exchange order as per their exchange policy. The return pickups were completed successfully.
However, during the exchange process, I was asked to pay the same amount (INR ****) again through Cash on Delivery (COD), even though the original payment had already been made. The exchange should have been free of additional charges as per standard policy and also what was showcased while placing the exchange order.
This issue has occurred for two jeans products, where:
The returned items were picked up by the company.
During exchange delivery, COD was applied.
I didn’t pay the additional amount and returned the products. I tracked the shipping company (Shiprocket in this case) and the product has been successfully returned back to Freakins but there is no update on refund and their customer service is unresponsive. +** **-******** this is the number listed on their website for customer support, but they don’t receive any calls, +** **** *** *** is their whatsapp chatbot number which is not responsive either.
This act amounts to:
Double charging
Unfair business practice
Lack of customer grievance resolution
I request the concerned authority to:
Direct the company to immediately process the refund for the wrongly charged amounts.
Take necessary action to prevent such practices in the future.
Ensure proper response from the company regarding my order details.
I am ready to provide order IDs, payment proof, and screenshots as supporting documents.
Kindly treat this matter as urgent.