Does that apply for all switches? LMB/RMB and scroll switch?

Leave the shell off and try them one by one, just click on the switch instead of the button - if they work, maybe you broke the hinge or the shell wasn't properly adjusted so it doesn't connect with the switch.

The Middle mouse button/scroll should work even if the hinges are broken, so you might want to give this a try.

Try posting some images.
Also give overclock.net a try, they have some avid g100s modders there that know the mouse inside out.

Finally fixed it. Had to find the right alignment and it popped back in and worked.

try sending it to cern

do you even elevate