Amazon India — Product not delivered on committed time and no communication thereof

Address: Bangalore

I have placed an order with Amazon India for a product on 20th of December. They have standard delivery date of 23rd December. But, when there was an option that If I pay additional amount, the product will be delivered to me on 21st December itself. I payed the additional amount as I wanted it to be delivered on 21st December as it has to be gifted to some one on 22nd December. As per their website and app, I see that the product was out for delivery on 21st December Morning 10 itself. Till 23rd December 18:00 hours it it not delivered. Escalated the issue to their customer care almost 5 times but in vain.
Amazon failed me in the following:
1. No communication related to delay in delivery was given to me.
2. When they take additional amount, they should see that the product should get delivered on time. That did not happen.
3. I heard only n number of apologies from their customer care and could not see an inch improvement from the day 1.