Flipkart - Defective product Received

I ordered asus tuf gaming a** from flipkart on * September **** then i got my laptop on * September ****.
After using ** to ** minutes my laptop gone dead.
I complaint to flipkart for replacement and they told me to wait for * days and told me that some technician from brand will visit your address and he will check.
I was waiting but no one came.
Flipkart told me to contact asus, So i visited asus service centre then they checked my laptop, Everything was good but when they enter serial number of my product on their system then it was showing that my warranty will expire on **/**/**.

Now i don't have any warranty on my laptop
Asus told me to upload my invoice so i uploaded but no one responses.

Flipkart wants doa certificate and asus is not providing me anything.

So i want to send legal notice to asus and flipkart.