In my point of experience Samsung and other companies screen should be repaired at official service center only. Minor repairs like mic and speaker can be repaired outside.
Recently, I spend 2500-3000 rupees outside on my aunt's Samsung phone. First replaced the screen, second time I saw touch issue with in few days and after few weeks it started showing vertical and horizontal lines. After that few days ago I saw touch issue like it was not responding and take it to shopkeeper and now it still has touch issue.
So, moral of story buy protection plan with phone and visit ONLY service center for screen repair related issues.