Didn't really understand if you've tested the switches or not with a voltmeter, even one of those ones that light up if there is a current flowing would do.
I would check the fuses to see if all are working, if you don't know which ones a trip to Halfrauds or GFS for a Haynes might help.
If the fuses are ok then check the switches, first to see if there is power to the switch, then power after the switch when you press it.
If there is power then go to the motor and see if when the switch is pressed it sends power to the motors, if it is recieving power check all the connections on the motor including earths, if this fails then ebay and new motors could becon you.
Others might shed some light on this, this is only what I would do
