Lenovo — Motherboard issue

Address:

Vellore, Tamil Nadu, 632004

My lenovo k6 power had ghost touch problems, when i submit my phone to service centre at vellore, they asked 450 inr to service the phone, time being i accepted to pay - now they say mother board has damages - has to be changed which will cost -6500 inr, when i ask my phone back they ask for 450 inr as inspection charge. Then what for service centres are there, there is nothing serviced/changed on my phone. Then why i should pay them 450.

Even lenovo online support had never reacted to me in favour. I will never trust their products any more.