Amazon India — Serial number not mention for the purchase done

I spoke to customer care and came to know all customer doesn’t get the serial number listed to claim warranty. I purchased a product on Amazon for laptop and today when I try to claim warranty with dell they are asking me for invoice which should basically have service tag number. Amazon lied that they do not provide this to any customer I checked with my friend he has it.

Because of Amazon I am not getting warranty claimed for the same purchase. However the laptop is still under warranty in their site.