Flipkart — exchange option to my old laptop

I have ordered an laptop from flipkart on Sept 30. using a exchange option where i was about to exchange my old working laptop (Dell Laptop which i bought 5 years before from US). flipkart asked for serial number of the old laptop on checkout page. where they gave the steps to get serial number (attached screenshot ) as get serial number from the invoice "or" from back of laptop "or" from typing a command in command prompt.

I have used command in command prompt to get the serial number and gave it to entered it while checking out.
On delivery the flipkart delivery agent came to door step for delivery and checked my old laptop. he viewed back of the laptop and said the serial number does not match. The serial number he shown is said "DPN:" I demanded it doesn't says anything about serial number, DPN doesn't mean any where close to serial number.also shown what the flipkart exchange page and also shown him the serial by which i got.He called his reporting person and queried about the ongoing issue and said we are only "EKART" the delivery partner and we dint have any instructions to get the serial number of laptop from command prompt and left without taking the laptop.

i requested call from flipkart customer service. I got call's only from the persons who are unaware about the exchange and have no knowledge on laptop. and i was been explaining the incident again and again.
one of the customer agent said to cancel the order and place the order again with the correct serial number as if i went wrong.

I had placed order through my credit card and the amount was blocked,
i had formatted my working machine and im being held without a machine right now, and flipkart doesn't concern about any of my problems.

I have been waiting and spent hours to avail an offer and ordered this, and flipkart gave fake promises and making fool of customers.
I demand flipkart to give the same machine i ordered at the same price as soon as possible tats my simple resolution for this issue