Savana wrong order recieved

I ordered a phone case from Savana and it was fast delivery so I recieved it withing 4 days. It was my first order so i got the case at ₹145. Its original price was ₹190. The package had the correct phone model written on it but I put it on and the camera and vol button placements were all wrong. I contacted customer service and they offered me a coupon worth ₹200 but it can only be used at a minimum order of ₹800. I told them I didn't need any other item at the moment so id like a coupon for the original cost(190)+shipping charges(99). Then they offered me a coupon of ₹300 at min value ₹1000. I refused that aswell. Now they have escalated my concern but my brother said you should've taken the coupon.

What should I do here?