I Have the same problem but on the bottom right side including the edge. It has got the clicking sound and the screen seems to pop out. I don't know what to do because my warranty had got expired on March 17 2016.
I Started facing problems battery problems just after 3 months from purchase and when that had not become much of an issue, I had problems with "No Service" due to which I had do change 3 different carriers, and now soon after that, the screen popping out and now it has worsened w the clicking sound.
I do not know if my phone would get replaced . I'm a student and I have spent my complete two year and eight months savings on this phone, and I don't have any more money to spend on any of the repairs. I would not like to pay any charge for replacing my phone, and if I have to, then I'm not going to buy any more Apple product.
This was my first Apple product and i am very very disappointed.
Now I think that a Samsung would not have costed much lesser than this phone and would run for 3 years without much problem.
Aple please help, I still have some hope in you.