iPhone 4s Cracked Screen and Flashlight Stuck On?

A few months ago I cracked my screen pretty badly. I took it to an Apple store and the Genius said that they don't make replacement screens and that I could pay $200 to get a new phone. I wanted to avoid paying that much money, so I didn't take that offer, figuring I could just take it to a place down the street and get the screen fixed for around $50.

So basically, I've been living with this cracked screen for a few months, trying to find the time to take it to get fixed. I was planning on taking it to the repair place sometime this week, but yesterday I'd noticed my flashlight was on. I looked it up online to see if other people had similar problems, and I tried everything. Resetting my phone didn't do anything. Hitting the back of the phone stopped it for about an hour but then it turned right back on again.

I realize that if I take it to the Apple store for the flashlight problem, they will immediately blame it on the cracked screen and try to get me to pay the $200 again. So basically my question is, what should I do about this?? Is there any way out of it, or do I have to suck it up and pay the $200 dollars?

I was thinking of just going to get the screen replaced and then taking it to Apple. Will they know that I've replaced the screen if the technician is really careful?