Amazon.in - Wrong and cheap product sent instead of expensive product you ordered

We ordered one mechanical keyboard with LED lights on *th June. It was delivered on **th June. On the same day when we opened the box inside the original box the normal cheap keyboard was delivered which can be bought from Nehru place at *** rupees. We placed the request for return on the same date but till date, no return has been made. We have approached the Amazon customer service several times and got feedback that they have delivered the right product. But this is false and fraudulent. We have received the cheap product inside the original keyboard box. If we would have known this would happen, we would have made a video when we opened the box. We have images of the keyboard which was delivered.
Request you to please help us in this matter. We want that return is made and the amount **** is refunded.