Adidas — Refund of Rs. 4619 not processed. Customer care is not taking my complaint seriously.

I Placed an order with Adidas (AIN[protected] which was delivered to me on 6th January 2022. Due to an issue with the product that was ordered, I immediately raised a return request with Adidas. The order was picked up by the courier partner on 7th January 2022. On 15th Jan, it reached the seller but they refused to accept my return and they didn't provide any reason why. I called adidas but they keep telling me to wait for 48hrs and I'll recieve an update regarding my refund. I have called them more than 5 times and they keep giving me the same excuse. When I Spoke to the customer service team they blatantly told me that they are unable to perform quality checks and the refund is therefore not processed. Due to a fault at their end. It has been almost 10 days. I cannot keep waiting for the refund especially of an amount of Rs 4619. They don't even respond to my email. Kindly assist in resolving the issue.