Myntra.com — against the aforesaid online shopping for delivery of wrong order

Address: H&M Hennas and Mauritz Retail Private Limited , Building 6, Square Logistics Park, Prakhyat Infraprojects PVT. LTD near Padgha Toll Naka on Mumbai Nasik Highway, Tal- Bhiwandi, Thane-421101, Thane, Maharashtra, 421101

A month ago i had ordered a jacket (H & m) amount of rs 3999/- but they had delivered me a wrong order i. E. A sweater amount of rs.1999/-, thereafter, on several occasions i had made complaints before their customer helpline services and they asked to to send a pictures of tax invoice, price tag, picture of that worng product and picture of a box. Although, i had sent all the picture as they had asked for but till date no response from their side and i also requested for my actually ordered product but they refused to send my actual ordered product.

Apart from that till date no one has come for pickup that wrongly delivered product and also i have not receive my money that i had paid for
And due to the negligence on their part i am facing various difficulties. So please help