After a reboot my iPhone 6 Plus now has someone else's Apple ID as the login??? I bought the phone 3 months ago brand new!

Question

The title says it all.
Some background info:
1. I purchased the iPhone 6 Plus new in the box at Target on January 10 2015.  The phone has only ever been mine, and it was not a refurbished device.
2. Absolutely no one else has access to my PC or iTunes, whether it be physical access or knowing my usernames or passwords.
What happened;
1. Phone fell out of my hand face down on my patio.  It had the leather Apple case on it.  Picked it up and sure enough the entire front screen was smashed.
2. Phone responds to touch, but not property.  I contemplate doing a backup and then resetting but I skip that and just do a "erase all content and settings"
3. Phone reboots and prompts me for this Apple ID (x*****@1*****.com) to log in.
4. That is NOT my Apple ID, not even close
5. I have no idea how the strange Apple ID is now embedded in MY phone, I have absolutely no way to access my own phone!
What I have done:
1. Called and spoke to several Apple reps; technical, Apple care, customer service, and then finally a senior supervisor named Matt.
2. Matt spent over an hour on the phone with me discussing this and he decided I should email him my proof of purchase directly through an Apple link that he emailed me.
3. I scanned every document I had with the receipt, paperwork, IMEI info and sent it over. He reviewed and says he will have to put in a request to do a force unlock which will remove the strange Apple ID and allow me back in
4. I set up an appointment at the nearest Apple Store to fix the phone. They do not know of the Apple ID issue and I was told they wouldn't be equipped to handle that anyway until the phone would be able to be unlocked.
5. So now I have to wait for Apple to force unlock my phone before (hopefully) my appointment on Tuesday so I can get in to it and they can fix it
Now from all the people I have talked to and all the Googling I have done I have found no reference to this happening to anyone ever.  The only related incidents like mine is if someone bought the phone through another consumer or sold it online and did not wipe their ID properly.  This however doesnt apply to me since I bought it from Target, unless they sold me some second hand phone.
Any opinions or insights on what it is that has actually happened to my phone from the time it broke and rebooted to magically having someone else's Apple ID as the authentication?
I really hope someone here has some insight.
Thank you.

Answer 1

The answer is very simple: You were not the original owner of the phone. Target sold you a phone that had been returned. You can verify the date of the original sale here: Apple - Support - Check Your Service and Support Coverage. I suspect you will find that the warranty expiration date is not one year from the date that you bought it.