Why is my front facing camera picture fuzzy after I got my screen fixed.

A

AC Question

So I dropped my phone (galaxy s5) awhile ago and demolished the top right corner. I pushed off getting it fixed because it cost way too much, and didn't really effect the use of the phone except for an ugly crack and the lose of the ability to use my front camera. you could see that it was picking up light but you couldn't make out any objects. I had a screen protector on it (that also got demolished) and I started pulling it off from the corner. With the front facing camera on you could see as i pulled the screen protector back and reveal that the camera was working perfectly! Needless to say I was really excited that I wouldn't have to replace the camera but just the screen. So i go to get the screen fixed and 100$ later the picture is just as blurry as it was when I originally dropped it. The guy that "fixed" it said that there is probably a scratch on the lens. My friend said that it might just not be lined up correctly. Can someone please tell me what sounds like might be wrong because I don't want this guy cheating me out of more money and if it's something I can fix myself I would rather do that at this point.
Thanks for any advise you have for me, if any.