HP India — the problem of display flickering, display discolouration, display going blank

I bought hp pavilion gaming laptop 15cx0140tx serial no:cnd82454zb on 29 may, 2019. I started facing problems of discolouration, display flickeringand blank display from starting of march. I have bought extended warranty with onsite service provision. So after these problems, i made multiple calls on the phone no. [protected]. But the only conclusion they came to was that it is a software problem and would not assign an engineer unless i would give them the proof of hardware issue by showing it on the bios page. So, in the end i myself took my laptop to the service centre, sysnet global technologies and after 11 days, they gave me my laptop saying that they replaced the lcd panel. But my question is why then the initial calls i made to the phone no. Stated above told that they would not assign an engineer? If i myself was able to give the proof, then why i need to buy onsite service? The problem is not finished till yet. When i bought my laptop back home from service center, after two days o[censored]sage the laptop showed the same problem of display going blank. So, even in 11 days your engineers cannot find the problem and they just did a hit and trial to replace the lcd panel and when i am asking them, they are saying they again need to recheck. So, am i that free a person to give my laptop again to them? Moreover 11 days are enough for the professionals to find what the fault is?
So, here is a strict warning from my side that even if i would give my laptop this time for repair, the next time i do not want any such issue again and if the same happens again, then you need to replace my laptop otherwise i need to go to consumer court.