Front Electric Windows?

Hello
Looking for some advice as both of my front electric windows have seized up and the passenger one is down halfway (I'm currently driving around with a plastic sheet around the window). Any advice on how I can get the window back up? I've seen the advice on taking the fuses out but this didn't seem to work - is this just for the rear windows?
I've noticed that this is a common problem for Megane's, needless to say I will be expecting my Renault dealer to foot most of this bill!!
Thanks.