How to remove the settings of a phone that was on display

[On3]

Unfortunately, I'm not sure how the forums work, so I hope this is the proper way to ask for help. You see, I recently used my warranty to get a new phone, since my old one broke, and the phone I got behaves rather strangely; everytime I lock it, it goes into this clip scene, just like the phones on display at a retailer. Not only that, when I try to access the "lockscreen & security" settings, I see the outline of a padlock, and I'm unable to scroll up or down, let alone change anything. That, and everytime I unlock it, the brightness resets to the highest possible brightness. I have tried factory reset and safe mode, and the issue persists(I kinda knew safe mode wasn't gonna do anything, it's clearly not a third party phenomenon!). I was wondering if anyone has had the same issue, or knows something that could help. Please and thanks in advance.

-On3

PS: I'll attach some screenshots for you to see 

[On3]

Edit: I can't screenshot the clip that I spoke about, but as soon as I get my hands on something that can take a vid or pic, I'll post it. Basically it's one of these types of video: https://www.youtube.com/watch?v=pMsQXzI06DY.

[On3]

Also, should I be concerned about the quality of the phone? Do they display the crappier phones, so they don't care if they get wrecked by a kid, or do they display the better ones to show premium quality(or they just display whatever!)? Thanks again to anyone who can help.

[Qatrium]

@On3

I think you were given a demo device, while I'm not sure if this is legal or not, but you can try dialing this code: 

*#*#73556673#*#*

PS: it might reset your phone in the process, so backup whatever is important for you.

[Jonas · Accepted solution]

Hi @On3, welcome to our forum and no worries, your post is in the correct place and you have included a great amount of information, which always makes it easier to assist you in the best possible way!

I agree with what @Quester wrote, it does sounds like you have been handed a demo device.

There are two different "versions" of a demo device.

1. The retail demo mode has only been activated in the device and can be turned off dialing "*#*#73556673#*#*" or if you go to Settings > Lock screen and security > Device Administrator and uncheck the Retail or Demo Mode option. This will remove Demo/Retail Mode from device.

2. The device has a demo software which can't be removed and as far as I know these type of devices are not meant to be sold or given to a private person, so if you can't remove the demo mode by following the instructions above, please get in touch with the retailer.

Let us know how it goes!