Xiaomi Mobiles - Refund of the product

I have placed an order of an MI phone on the *th of June ****. I used their exchange coupon for this purchase. The delivery guy has refused to give me the phone citing that the old phone does not qualify for an exchange. So I have decided to return the product and requested the delivery guy to send it back to MI for a refund. This incident happened on the *th of June. The turn around time for the refund was around ** days. However, to my surprise, the product has not reached the company yet and from the **th of June, it's lying at Hyderabad. I have called the customer care multiple times had a chat. Sent numerous e-mails. Have attached all the screenshots. I don't have clarity on the refund yet. Complaint number from MI is WO: ISIN**************-****. Complaint number from National Consumer helpline is *******.