Huawei — honor 9 lite has display issues - rainbow colours

Address:

560102

This is about sr[protected]. I was regular honor customer and upgraded from honor6i to honor 9i lite before 7 months - purchased from flipkart. However, just within 7 months, phone's display is gone - its showing rainbow lines on whole screen. This happened without any physical damage - one day while driving in car and when phone was connected on bluetooth, i came out of car and saw that it suddenly lost display.
I went to huawei centre and to my surprise, they tried to manipulate by showing physical damage and so, they can not replace under warranty! They showed some minor wear-and-tear on egde (Not even on screen) and saying thats the reason display is gone! Any phone which will be used for few months will have some wear-and-tear and using it to reject warranty claim is cheating. I need to raise this case to consumer court for compensation.
Can huawei prove that in what condition if phone will have physical damage, it will only be in one edge for few milliliters and how it will affect display screen? This is just dishonesty and intentional cheating - would need to get lawyer to sue them.