Physics wallah - Refund Not Given

I bought Banking Mahapack from physics wallah for ****, but then I realised this was not what I needed, so I decided to change the course. Physics wallah doesn't give refund, but allow you to change batches if they are of same price. But the batch I wanted to change was of **** rupees, I contacted them saying I am ready to pay extra to change the batch, but their agent told me to first buy the new batch and apply refund, Which I did. Now I am waiting, but they still haven't initiated the refund, not I am able to connect with them via any means. Their customer care is not working, they are not answering email or message. Please help me get my money back. I am attaching screenshot of payment receipt of both batches and the message where their agent told me to buy the new batch first then apply for refund.