Amazon India — Wrong item received from amazon

I have ordered DELL LATITUDE 3542 Laptop 65WHR battery on 25th may it got delivered on 28th may, after opening package i found out it's different product i.e. 4oWHR battery, on escalating the matter to amazon, i have been told we'll investiage in this matter meanwhile i have requested for return/replacement of the battery it had been picked on 30th may, after a week discsussion and 15+ times call i have been informed that i won't get any refund/replacement as i have sent wrong/different item. i have shared proof o[censored]nboxing video and images as well but they have not listened to my query. i have been bombarded with threat mails for not giving refund/replacement.