Flipkart — I want to return my camera

Hi, I ordered a camera during the big billion days and by mistake I ordered the canon Eos 200d instead of canon mark II.

Later I found the issue and when I tried to cancel the order, it is showing that I cannot cancel since the order is already dispatched.

So I thought ok let the product come and I'll return the product.

But after I received the product, I'm not able to replace it. It is showing me that since it is a open box delivery I cannot return it.

Can u please help. I want to return the product and want to buy the Canon Mark II camera.

I don't want the money back and I'm ready to pay the difference amount but please take back the product.

I've not yet open the plastic of the product. It is kept as it is after it is delivered as I don't want to use this product.

So please help me. I've been a loyal Flipkart customer for more than 5-6 years and I've purchased 1000s of product from flipkart