Problem with wall

I think that had posted in the wrong area so i'll post here:
Ok I design a super-simple level but this have a problem,when my enemy or my player collide with some wall it is dragged out,how can I make that this wall don't be throw at each collision

Sorry for my bad English
When I insert a rigidbody+Mesh Collider the same thing happen and when I only insert a Mesh Collider enemy crosses the wall

 

Why would a static wall, that shouldn't move, need a RigidBody component? You obviously don't want that. So get rid of the rigidbody and concentrate on figuring out why the collision isn't working. The wall should be a static collider; the player may or may not be a rigidbody collider. See the Physics Components documentation for more details.

 

Remove the rigidbody. Just need the collider, as laurie says you dont need a rigidbody for static asset. You'll use a rigidbody only if you need to apply forces.