Swiggy — not getting the delivery of my food

I ordered food from chowman through swiggy on 31st august, 2018. At around 10:18 pm i received a call from a phone number [protected] which lasted for only 20 secs and cut off as i tried to receive the call. There was no information that the call was from swiggy. I called this number four times from 10:56pm to 11:43pm. Every time i got the same response that "the number is incorrect. Please check the number." while checking the phone i found that there was a message from swiggy that, "your order #[protected] has been cancelled since you failed to respond to our delivery executive's calls."
May i ask swiggy that who the so called "delivery executive" was who could not deliver the food even the restaurant is hardly 2 kms away from my home? My building, being a single tower may not receive the phone connection at times at upper floors. But couldn't the 'executive' call me once more and that too for a longer time? What special instruction does he need to deliver food to a well known building? Why does swiggy harass the customers by appointing such inefficient "delivery executives"? Is this my failure to answer your "delivery executive's" call or it's his failure to find your customer's address? I consider it as an unacceptable customer treatment from swiggy.