Myntra.com — Sends me the wrong product and refuses to pick up

Placed two orders. Opened an order but found that the size doesn't fit me. So, didn't open the other package but requested return for both packages. Delivery agent comes to pick up the unopened package (Return details
Return Id[protected]). He rips it open and finds that the tags are intact but the item does not match Myntra's photos of my order. He refuses to pick up citing quality check failed and marks the reason as item tags were missing.

I contact Myntra with photos proving that item tags was intact. They harass me by putting the pick up on hold citing false claims against which I have proofs.

Please help me sue Myntra for the hassle and damage to my reputation.