how to get stock rom / unroot / make it look out of the box

[ddann]

Hello everyone, I recently got a Tab 3 for Christmas. I installed a recovery tool like that clock work recover but not that one, and installed a .zip file that gave me root access. I found out how much my wife got ripped off on the price and I want to undo everything to make it look out of the box. Does anyone know how to do that? I am trying to make it have the stock rom, rock loader (for lack of better terms) and wipe all my personal information off of it. My wife paid enough to get the Note 10.1 Tablet. I feel ripped off. I just don't want the person to try and say I can't return it because I modified it. thanks