So in short, am trying to do:
1- fix face1 + displace face 2 in xoy plane -> get resultant configuration [configuration 1] (I successfully done)
2- block configuration1 so that body doesn't go back to undeformed position (sucessfully done)
3- displace face 2 in z direction with no constraints on face 1 (unsuccessful because it's considering that face 1 is always fixed though I didn't write such a constraint in step3)