Lenovo — Phone got damaged within 10 months but charging extra money & no warranty

Address:

oberoi realty ltd, 3rd commerz, international business park, oberoi garden city, goregaon east, mumbai 400063

I purchased Lenovo Z6 Pro Black, 128 from Flipkart on 11 jan 2020 having invoice no FAAAHO[protected] of amount Rs. 29999 and IMEI no [protected] and IMEI2 [protected]. the colour of the screen getting spread internally when i showed this to service center they are charging extra rs. 8000 for this. i haven't damaged my cell phone then too i have to bear extra 8000 repairing cost why it is not covered under warranty. please advise me what i have to further do to either get the same repaired of replaced.