Adidas - Refund not initiated

I had ordered a Adidas shoes from Adidas official site i.e. shop.adidas.co.in on **rd November

When the shoes arrived I came to know that the size I had orderd is small for me
As I called Adidas to know how can I grt them replaced with a bigger size
Then
They said they do not have replacing process but they will do refund
And said that Firstly they will quality check the product which I will return and then they will process refund

Then I packed the courier as I recieved
And then after a few days
They mailed me that the product you had send has failed in quality check and they send me a aatachment of the shoes they recieved
The shoes they recieved was completely different from the product I send and I recieved

And, now when I called them
They said that we will look into the matter and will help you surely
And will aarange a callback within ** to ** hours
But,
I didnt get any call from them

Then today I called them after *-* days
They said that the case is closed and no refund given

As they said I have send them wrong product
But I send them the same product I recieved

When I said thatvkindly help me in this
They said its all over from our side
And you can do whatever you want

So please help me