What's the matter with this S4?
So I bought a Windows Phone months ago to see what it works like but I think it's utter garbage. I put it up on Craigslist and some guy sent me a message asking if I want to switch it with his Galaxy S4. The S4 is still worth more than the phone I had so I agreed.
Almost everything is working fine and I'm very happy with it but there is one problem that I'm having. I went to the Software update thingy to see if it was running on the latest version of Android and it said: your phone is customized so you can't update. I normally don't root any of my phones because I'm too much of a noob for that and I'm sure I'd end up with a very expensive brick, so I didn't know what to do now.
I did some Googling and found out that I could unroot the phone with SuperSU (which was on the phone when I bought it). I run SuperSU but it says: "There is no su binary installed and supersu cannot install it. This is a problem!" Upon clicking OK, SuperSU closes. I also downloaded a program in the play store to verify if the phone was indeed rooted but the app says that my phone is not rooted!
Meanwhile, I still can't update to the latest Android version and an application that I use to watch TV refuses to work. That application says: "because of copyright issues, television is not available on devices of which the software was adjusted by the user ("rooted" devices)." So according to the TV app, the phone is rooted, but according to a root checker app, it is not.
*sigh* How can I get the phone back to like it would be if I would buy it in a store? I don't want it rooted or customized or anything. I just want to be able to use the TV app and update to the latest Android version. Anyone here who can help me out? I would really appreciate it, thanks a lot in advance!