Amazon India — Regarding not providing my refund amount for the returned item

I have ordered a camera from Amazon App on 23rd june 2025 . It wasn't working properly so i have choose to return it, when i contacted to Amazon customer care executive they told me that it is self return basis product but they didn't mention about self return in description of product. I have visited post office about 15 km away and place the return of product on 3rd july 2025 by speed post and it is arrived at 14 july 2025 . When i call to executive they still didn't issue my refund for the item . I have suffering from almost last month, i have paid courier charges, i have paid petrol for 15 km, my didn't complete because camera was defective. Please do something for this i have waiting own money and still i didn't get it .