Vectra estate Rrear wiper and washer not working?

I have an 08 Vectra Estate. After some accident repair at the passenger side front my rear wiper and washer aren't working. The fuse is OK and the switch clonks to signal cancellation. I phoned the garage and they said they hadn't touched the back, maybe it was a fuse and to bring it back. However they are 200 miles away so if anybody can suggest what I can do myself I'd be very grateful. I'm sure they must have left something disconnected, but what and how do I find it?