Flipkart — Used Product received for Eureka Forbes Aquaguard/Water purifier 7L Amaze

Website:

Flipkart.com

I had purchased Eureka Forbes Amaze 7L RO+UV+UF+TDS water purifier from flipkart on 11th June. An installation was arranged by Flipkart/Seller(of water purifier) and the technician visited my home for installation.
On visit, I was told by the Eureka Forbes technician that the product is already assembled (as the unit was already assembled and used by previous buyer). In-spite of raising multiple request of Replacement as well as return there is no resolution was that provided to me.

The photos I have attached the the exact state in which the product was delivered & it is evident from the photos that the screws were already assembled & the packet was already teared.
Kindly provide me the resolution because the customer service executives are not resolving me complaint