Amazon India — Wrong product delivered and customer service

Address:	560066
Website:	amazon.in

(Account ID: [protected])
I would like to highlight my last purchase experience. I had order Swiss military Bluetooth speaker, which was supposed to be delivered in 7-8 days.
On delivery date,
At 11:30 AM, Delivery guy called and said please come and pick up your parcel and pay 999/- (COD). I received the product and paid money.
At approx 1:30 PM, I received another call other amazon delivery guy. I asked him which product. he mentioned Bluetooth speaker. I said, i have already received the product, this might have been come by mistake. so cancelled the order.
Then in night, when i have opened the product, I was surprised by seeing it. They delivered Nova hair clipper instead of Bluetooth speaker.
I have taken the pic and forwarded to Amazon and also talked with customer care.
He agreed, this might have been done by mistake and initiated return pickup.
Now i returned the product and called amazon customer care and he is denying about it. He said, product is not delivered so it can't be returned (which is already returned to pick up guy). and every time i call i need to explain from start. it's frustrating service which has never been expected by Amazon.