2008 Ford Ghia Turn signals come on after car stops!

Dear car persons:
We are in Europe, and are borrowing a Ford C-MAX1600 TDCI Ghia. We are utterly baffled by this : the car works fine, but when we turn it off, the left OR right turn signal comes on, and will not go off. Jiggling the turn signal arm does nothing, and, what's worse, the car will not electronically lock in this condition. We are having to disconnect the battery every time we are done driving, and the service people here will not see us for two weeks. Help!