Swiggy — charged without proper food

Address:	Rangareddy, Andhra Pradesh, 500035
Website:	Swiggy.com

The delivered product is very bad and it was cold and smelling.
Immediately contacted swiggy and they said they can't refund complete amount as they don't have such option.

Why we have to pay for something we have not given properly?

Swiggy did this second time in a month and they have never refunded me instead offered coupons on next purchase for half the price of my order. I have lost 800 almost on these issues.

Please help me with way forward as i want to sue for these actions.
I have all conversations and call recordings along with emails.