Nykaa - Refusing to process refund for Cross Border Product

Purchased a cross border product from Nykaa (Hindash that came from Dubai). They sent me the wrong product. Was unable to initiate a return or replacement from the Mobile app. When I read the policies, no returns or replacements are applicable for cross-border products. Only refund will be initiated within * days. Hence I intimated them via mail and send them pictures of the received product. In the following mail chain nothing was said about the return or replacement that could be initiated. I also informed them when I placed the same order again. Again, they did not let me know if the initial product can be returned or replaced. Hence I was just waiting for their refund and gave the wrong product to my sister.
After ** days they tell me that the product has to be returned. When I informed them that since their policy mentions no returns/replacement and the product is used, they deny me the refund saying "Product is used/altered"!