Xiaomi India — yellow patches on display

Address:

Appasons Mobile Gallery,1St Floor, Suhara Arcade,Axis Bank Building,Aarat Road,Kannur,Kerala,670001, Kannur, Kerala

I'm using Note 5 pro for the past few months and it's started showing yellow patches on display overnight after usage of just 4 months. I visited the service Centre in Kannur of State Kerala and they says I need to keep the phone their for Seven days. How is it possible.?? This is very bad. And my warranty will finish with in two days. What do I do.?? I really appreciate if you help me.. I googled about the issue and there I can see a lot off people facing the same issue I did. This makes me started loosing faith on Mi brands. I'll never recommended an Mi brand to anyone here after.. I'm really look forward for your reply.