Myntra - Return Declined after pickup

I purchased roadster sweatshirt (M size) from myntra @Rs***. I find this size somewhat loose then i ask for replacement. Order replaced successfully by myntra. Then i found S size also loose. So, I ask for return. On **th October, delivery agent called me and picked up the product at around *:**PM. At *:**PM, I received a message from myntra that your product is mismatched so return pickup fail. But delivery agent picked up the product from me. After that, i tried to contact myntra many times but they said that we didn't receive your product. I ask them delivery agent contact no. that have picked up product from me so that i can directly ask from that person. Myntra said they didn't have any direct contact with delivery agent. So, i asked them to ki meri bat krwao with your supervisor. They have given me time * times but i never received call from supervisor. I want to resolve this issue. I have returned the product then how they can say that i have not returned.
Below is the script of phone call (at *:**PM) when delivery agent called me for pick up. I have also recording of this. +************ is the contact no from which i received call.
हैलो - हाँ जी मैडम नमस्कार - हाँ जी - जी आप रिटर्न थी मिंत्रा से - हाँ जी भैया - तो कहा से लेके जानी है - भैया ये पता है आपको पप्पू की कोठी - हाँ जी मैडम - इसके पास ही है भैया - बाहर मिल जाओगे अभी - कितनी देर में आ रहे हो भैया - बस * मिनट में आ जाऊंगा मैम आप बाहर मिलियो - ठीक है ठीक है भैया - मैडम मेरे फ़ोन की बैटरी लो रही है और ये चार्ज लगा रखा है मैं साथ में नहीं आ पाऊंगा इसको - ठीक है ठीक है भैया - ठीक है फिर बाहर आ जाओ - ओके भैया

After **-** min, delivery person came and picked up the product.
At *:**PM, I received a message of product pickup failed.
Myntra is asking from me delivery agent information who picked up product from me but How may I know the name of the agent who picked the product as they never mention the name of the delivery agent in the message before pickup. they mention name of the person only after the pickup when they send message “Product picked up successfully by………… agent”.
Order ID: ******* *************