Maze game hittest problems

hi guys can anybody help?
i’m currently building a maze style game, but my character seems to be able to walk through the walls. i have tried the getbounds and x y style of detection but this does not always work. i have seen similar games but they all seem to have one thing in common and that is the maze walls are the same height or width as the character, mine however has thin walls. i dont know if im building it right, my maze walls are all in 1 mc or should the walls be split into multiple mc’s that make up the entire maze.

cheers