Myntra.com — Return Product found with Ecomex and Myntra

I had created Return ID [protected] for Flying Machine Navy blue sweatshirt on 1st October 2.10 pm .The order Id was # 1183614 [protected] . The Delivery Agent arrived at 3.30 pm 2nd October & gave his name Sumit Thakur and was using Phone Number [protected], he said his DP ID was13867.
Extra products picked up in the same parcel had Return IDs [protected] & [protected]. Upon asking pick up receipt the agent behaved rudely and misbehaved with me. He even threatened me with offensives.He then left in a hurry. I have till now not received any refund or the product itself . Upon raising query with Myntra my query is not being resolved.
I further complained about the same to Return Pick Office Ecomex Manali and on October 19 I received call from their Supervisor Praveen Kumar with Mobile Number [protected] that they have found my product in their office which has been lying their because of Sumit Thakur. I have recorded all conversations with him where he has admitted and acknowledged that his boss sent a mail to Myntra about the same but they have denied return because date period has elapsed.
What is my fault in it if Myntra Pick Agent willingly tried o steal my product and got caught?..I returned the product within return period and I have neither received my product nor refund to date.The Product is with Myntra and it is harassing me for their own mistake and blantantly lying that the product is not with them.