Do not want the ball to come out of wall during cycling

Hello to everyone,

I am trying to study the slope with ball distributed being inside the wall and calmed to null the velocity. Thereafter, the contact model is called and with ball property and attribute being given.

After this approach the modeled, is cycled and till 10,000 steps by fixing the balls at bottom of base and in height near to wall.

The model is solved and able to see the ball are settling and ball being moving out of the wall.

I want to know how can it be prevented and load to be applied on ramp

After simulation i am getting this as output.