Part of touchscreen is unresponsive
I have been using the iPhone 5c (16gb) for almost two years, a few months ago a part of the touchscreen (a 1 inch width strip in the left side allover the screen length stopped responsive and i can't use that part and most importantly I can't use the character on the keyboard that located in that strip.
It had never been into water and I have used a tempered-glass screen protector and an original Apple iPhone 5c silicon case.
It is really bothering and unable to use, I wonder what could have caused it and how can I fix it??
the weirdest fact about this, is that this part is working and responsive in the start screen (slide to unlock) and I can slide it and type the password as well.
Would like to get some help and see if anyone else had it?
iPhone 5c, iOS 9.0.2