Restitution coefficient - 3D contact

Hi,

I am currently trying to do a simple contact mechanism simulation which is applied on a bouncing ball. I'm using a 3D contact to model the contact between ball and ground. However, I remark that there isn't any options to add restitution coefficient. Can you please tell me where can I add my restitution coefficient in order to make sure the ball bounces back upwards when it touches the ground.

Another question, I found it's weird that the normal force of contact isn't coherent to the position of ball when it's in contact with ground (please view the graphs below). Normally the normal force should achieve a peak when the ball is in contact with the ground, but as you can see in 2nd pic, I only have a constant even at the contact time. Can you please enlighten me where did I do wrongly? 

P/S: the results below is achieved using 2D contact (cams), not 3D contact as mentionned above.