[Sprint Samsung Galaxy S7 Questions & Answers] Centerspike:
Exactly, I just kept getting the run-around for sprint.

I made a lot of progress though, and learned some valuable information for this thread as well.

I talked to an escalation manager for hours, and thought I was making some headway, but ended up cycling all the way back to the beginning when the account services said the previous owner needs to call in and take care of it.

At that point I was fed up. As much research as I have done, I decided to use SamMobiles unlock tool. I was curious how they could provide real time unlocking.. I selected my phone model, "Can unlock without root". Great! I paid roughly around $17USD, and downloaded the software and used the login that was immediately sent to my email. Got everything ready, clicked Unlock.

It was then I got an error that my phone COULDN'T be unlocked without root on the current firmware! It said root my phone then come back and try again. I was pissed! The whole purpose was to not trip KNOX and not be able to use Samsung Pay, etc.... Then I remembered that the phone recently updated to a January update (not Nougat), but a 400mb file through Sprint... I tried my luck at reflashing the stock firmware before the update, and then was going to find stock firmware from early 16, but decided to try to unlock one more time to see if that did the trick.

Unlock success, within just 30 seconds. I was relieved. I put in my ATT sim card, and sure enough, I saw bars appear, but no LTE yet. I found ATT APN programming page for new devices and programmed ATT APN settings, and then once that was done, the LTE started working and I had data. Awesome.

But it didn't stop there. Now the Sprint Hands Free Activation kept popping up, trying to activate through Sprint Servers. It didn't go away. After researching, you can't just disable it because it causes problems with notifications and other things. You can just force stop it, and it's only good until the next time you start your phone. No good for me.

I then thought I would try to change the firmware to the G930U, instead of the current G930P, to get rid of all the sprint crap, and just have a brand free phone. I flashed the AP and CSC, success. I was surprised. Things were going smoothly now. The phone now thinks it's model is G930U, but curiously enough, the Baseband still shows G930P. I didn't know if this would affect anything at the time.

Here's the interesting part.

Samsung Pay popped up at that time trying to get me to set it up, all was working, so I closed out of it, and continued to set up my phone. A day went by, and I decided to go ahead and add a card to Samsung Pay. I noticed the slider at the bottom of the screen wasn't there anymore, so I opened Samsung Pay from the app menu. It was then I got the message "Access to Samsung Pay has been denied. Unauthorized modifications have been made to your device. Contact customer service for more info." Below that, it had a link to call customer service.

At that point I kinda freaked out, thinking I voided the warranty somehow and knox was tripped, so I rebooted the phone and checked in the Download mode.. KNOX was not tripped. Warranty was not void. - - - - I then looked it up online and all I could find is links to show where people have tripped KNOX. So interestingly enough, Samsung Pay will not work in some cases where KNOX is NOT tripped.. Which is a shame, because I can't handle that Sprint Firmware Bloat crap. I'm curious if I can change Baseband or other things to keep that from being an issue? Anyone have any input on this?

So all in all, I accomplished my goals and successfully have my phone unlocked. I do want to confirm I was able to do it through SamMobile, with little issue. I ended up switching to T-Mobile One yesterday, and thinking about switching to the TMO firmware.

I hope this post has helped a few with increasing their knowledge from my experience, and if anyone has any advice or comments, please feel free to do so.