Paytm Mall - Refund not received

I have purchased a product from paytm mall on due to size issue I returned the product. Though I returned the product I didn't get a refund. The purchase was made on **th December ****. I requested to return the product and the same was collected by them on *th January ****. After that, on the *th January, I got a message from them that" return request has been rejected". As I have already returned the product there is no question about the rejection of my return request. I communicated with paytm helpline the problem is still not resolved and I didn't get my money back. I stuck in the situation that, I returned the product and I didn't receive the refund.