Sprint/Boost galaxy S3 no options for disabling KNOX, will not root.

[Ian Stephens1]

*please excuse me if there is a thread for this as I couldn't find one that specifically suited my situation**
I just bought an S3 for boost, it is unlike any
other S3 I've seen with how it operates. I think it may have a custom ROM installed. There are no options to disable KNOX. Any where on the phone, the settings menu looks different as well. I have tried many ways to root it and it won't take, SE for android is constantly in my notifications. I tried an app Disabler but it won't work as well. I think it has been flashed with a different kernel, ROM etc to be close to stock but is very limiting.
In the about phone on the very bottom it says SE for android: permissive but it won't let me click it. Developer options have been enabled by me. In manage apps I can FC all the Knox services but not disable.
Running on android 4.4.2

I don't know a whole lot about phones and am somewhat of a noib with technology but not a complete *****. I've tried all ways I've found online to fix this thing and possibly root it and have been unsuccessful.

Thank you for helping.