Flipkart Asus - Product not delivered on promised date

I am a Flipkart Plus customer.
I have ordered Asus ROG * Phone on **th August **** on Flipkart. While booking the order, delivery date was promised as **nd August **** at my given address. on **nd of August, i got an msg & update on Flipkart order page stating Your order could not be delivered today and will be delivered in the next * days. Later i got **th August as a delivery date & thought Flipkart will honor the delivery commitment time. But surprisingly, on **th again i got an msg stating that, Your order could not be delivered today and will be delivered in the next * days.
I keep on calling Customer care & asking for the delivery. Flipkart Customer care is useless & really pathetic experience. I requested them to share emails if of grievance officer or arrange a call with senior manager to discuss about delivery concern but customer care executives denied to share the details & didn't arranged the call.
Now days all companies are working towards Customer satisfaction but Flipkart is not working towards it. Flipkart is taking customer granted..
I wants to escalate this matter with higher authority of Flipkart.