Flipkart - Defective HP thin and light laptop neither replaced nor refunded

I had ordered for the mentioned laptop (Serial no.*CD***J*PX) on **th May, which I received on *st June. Upon using the laptop I started facing performance issue. I raised a replacement request for the same on *nd June. Flipkart just contacted the HP and raised a request for servicing for the defective laptop, instead of going for replacement. After multiple follow-ups and raising case against HP in consumer court, the technician visited on **th June and after making all the kinds of updates of BIOS and drivers couldn't resolve the problem. He then asked for the invoice that I got from Flipkart. I showed him the invoice, upon which he said that he won't be able to proceed with the case as the invoice doesn't have the serial number of the product. I immediately contacted Flipkart and after much struggle was able to get through to the customer care of Flipkart. I told them about the missing serial number info on the invoice upon which they merely told me to tell the technician to go ahead with the serial number from the product and the product box. I asked them to tell the same to the HP technician, but the technician was adamant and started showing the HP policies.

Now the case is rejected by the HP, citing the excuse that the invoice has not got the serial number printed on it. Flipkart is not doing anything and keeps on giving me dates to get the issue resolved. Due to their negligence, am stuck with a defective laptop, which is showing more erratic behaviors day by day.

Please get Flipkart to either replace the defective laptop without the HP intervention, or please ask them to provide me with an invoice of the product with the serial number of the laptop, so that I can make HP proceed with the complaint.