My iPhone 5s fell out of my pocket and smashed the glass. Everything still worked perfectly. The touch screen was just as responsive as ever, and Touch ID worked fine. I had the glass (whole screen maybe?) replaced a few days later only to find that Touch ID didn't work and roughly the bottom right quarter of the screen was extremely glitchy (in regards to touch responsiveness). They replaced it with a white screen because they were out of black. I brought it back to have them repair it again and replace the white screen for a black one. They found out something wasn't plugged in completely with the Touch ID sensor. After this repair Touch ID is working again, but now roughly the bottom half of the screen is extremely buggy, in regards to touch responsiveness. 9/10 touches are misinterpreted, and the phone reacts as if I were scrolling, usually down, but often in other directions too. When I intentionally scroll the phone will almost instantly jump in a random direction about 3 or 4 times as far as it should. Sometimes when this happens I can hold my finger down and it will continue to jump in that direction.
What might be the problem? Is it possible I got two lemon replacement parts? Is there anything I should have this repair shop look for?
Edit: After taking it in once again and having them take a look at it, they found that one of the cables (digitizer cable?) was pinched. They didn't say if they replaced it or just removed the pinch point, but their attempt to fix it failed again.