After logging the complaint through mobile app, I got the call from customer service yesterday (this is within 24 hrs SLA) and scheduled an appointment with me today at 11am for the reported issue
Service technician came this morning half an hourly to the appointment time. He had all the armours (right tools & computer etc) in his bag. Once the USB port is accessed, he could finish the firmware update within a minute.
Now the middle portion of display is sensitive enough and working fine.