How can i fix my passenger side window that won't go up or down?

How can i fix my passenger side window that won't go up or down. I have a Renault Megane Dynamique 1.9 diesel 53 plate. The motor has been now been taken out by the rubbish garage that i bought it from so that he could find the part that he thought was broken and now it is wedged up with a piece of wood and we can't get the garage to fix it as he keeps making feeble excusses, i have been waiting since September 2007.