I got the used product from e-commerce platform

Mam.. nI bought a product from an e commerce platform which I got usednThen I put the product on the return request on the same day and I gave my valid reasons and screenshot also.. Then after 2days they cancelled my return request.. Then I called them again and this time they accepted my return request for replacement.. But again two days later they cancelled my replacement againnAnd they accepted my refund after calling then more than 15timesnAnd they said after 7 seven days the delivery boy will come to take back the productnBut the delivery boy came next day and I got fever that day due to which I couldn't receive his call but he cancelled my request within 24 hours without confirming to me and gave the reason that the product was mismatched which he gave a false statement without seeing the product and cancelled within 5hoursnThen I called them again and they said my request is valid and correct and told me to wait 10 days morenAnd they again cancelled within 2daysnPlz help me