The electric shower stopped working - isolator switch?

The electric shower was switched off but the isolator switch jammed on and could not be switched off. The electrician came in and sprayed wd4o on it which we questioned and said it worked now but the shower does not work still. The elcetrician had not checked the connections inside coud this be the problem still? Hence to say we are not using the same electrician again due to his practices!

moggie
April 2012