@Omnija

You could try entering 0000 as your product code in your mapper file. Alternatively, you could use xboxdrv. Instructions below:

https://www.reddit.com/r/RetroPie/comments/3mcf4y/kodi_with_xbox_360_controller/

@shades42

Have you tried running the loadmap program from a terminal on the pi? You should see key presses written to the terminal (you may want to change the key presses to letters rather than esc/ctrl for this).

Alternatively, you can use your controller as a xbox 360 controller and try the link above.