Amazon - Defect product and misleading information of product

I purchased a oxygen concentrator thorough Amazon where it said purity of oxygen is varies ***to **%. When I received product after paying *****. The product booklet itself says it's not for medical emergency. And the product's output of oxygen purity is constant as per flow rate. At *lpm(lom -liter per minute)purity is **% and *lpm-**%, *lpm-**%, *Lpm -**% , *lpma-**% . *lpm-**% and *lpm-**%. When I asked for return or for other replacement of machin which atleast can give **% purity at *LPM for medical emergency during covid time, support team consistently kept on saying to contact manufacturer even though themselves couldn't get the contact details of the manufacturer. Somehow when I contacted them the manufacturer they gave a video link of product demonstration but nothing else on the issue. After this also Amazon support team has been asking me to get in contact with manufacturer and they can't do anything. Why would anyone wants to buy a product which gives ** to **% purity of oxygen when we get **% purity in atmosphere for *****. This is not a case of product defect, it's a complete misinformation of amazon which led me to buy and Amazon is throwing the ball to the manufacturer. I request your help on this. When I purchased machine one week back the price was ***** and now it's price is *****. Kindly do me the needful.