Flipkart - return rejected

I purchased Adidas Lite Racer byd Running Shoes For Men (Black) (ORDERID: OD******************) from flipkart on Moday, Dec * **** for INR ****
I initiated a request for return of the same on Tuesday, Dec *.
The guy who came for pickup rejected the return because the shoe was not having the "price tag" with it.

The shoe never came with a price tag in first place, and, if it is a mandatory thing for the return,
it should have been mentioned at the time of placing the order.

The product was delivered at office's gate to be sent to the mail room.
This is what happens most of the time.
Now, once the order is delivered, there is absolutely no way of returning it back if the product have some missing items (a price tag in this case).

Flipkart says it is a flipkart assured product, and so the price tag should have been there.
However, the product I received didnt have any and they are not ready to accept the return now.

Flipkart has nowhere mentioned that a price tag is an expected item if the product is flipkart assured.
How would a customer know what to check and what not when the product is delivered?