I had faces the same issue after an update and all of the sudden i visited service centre first they totally denied to fix it free of cost but after a long conversation and get connected to customer care anyhow i manage to submit my phone today let's see if the display changes free of cost. I have a notification regarding FOC replacement if you want then ping me I'll send it to you. Don't worry if your phone doesn't have any type of physical damange or liquid damage it will repair free of cost only thing which need to keep in mind is not to open phone by yourself or any local shopkeeper because service centre will diagnosis and may be they wil reject your claim for this.
