I got scammed by Lenskart, what do I do?

I got tricked into paying 5040 to Lenskart for 2 eyeglasses and a gold membership(i wasn't informed about the price of membership while payment). I've been trying to get my full refund but they tell me they can only give partial refund as the "membership gold" is non refundable. The membership costs 840.

Edit: I spoke to the store, it seems I'll be getting my refund in a few days. I'll update later(when it happens)