Faulty repair done by apple, what to expect...?

hello,

So to begin, I got my new iPhone 6 plus about 5 months ago. And in February, I noticed while in darkness a blue pixel...signs of an obvious dead one. so, I scheduled an appt at the genius bar to have the screen fixed. Things went well, and they fixed it. Now, fast forward about a month, I notice my Touch ID is not behaving properly, so I checked for software updates, and reset my fingerprints. Nothing helped, so I just turned it off. shortly afterward, the screen would freeze in its place and not let me control it until I restarted the phone. Now, from what I understand, all of these parts, mainly the Touch ID sensor, and the screen touch sensor array, is all one module. So, concluding that all standard software fixes did not work, I can only assume the screen repair was poorly done and faulty. My question is this: is it outrageous to ask for a completely new phone, as this has happened to others in my area as well, or will they push for a screen repair once again? Also, its a 6 plus, but woold they give me a 6? Is it against policy?