Swiggy — order cancelled at the time of delivery

Address:

Muzaffarpur, Bihar

I ordered food around 9pm and i was informed that food will be delivered within 42 minutes approx. I also got the message that 'your food is being preparing'. But when the delivery agent reached the seller then he called me and told me that your food is no longer available and the shop is getting closed. So my complain is:
1. If the food was not available then how would i got informed that my food is being prepared and also i got informed by delivery agent at the end of estimated time.
2. I paid the amount through amazon pay and i got the cashback for the same. But when i got refund from swiggy then the refund amout has been adjusted with the cashback. However i didn't cancel the order so how the amount got adjusted with the cashback.

They are making fool to customer by providing wrong information on the app. It was the mistake of swiggy then why should i suffer.