What model year is your GS? If it is the current one, there is something called the Winter mode. In the Winter mode the wipers do not go back under the bonnet. (for snow etc ... purposes).
You can use a little force to click/bend the wiper arms back to the normal mode. Don't be afraid, just hold tight to the wiper arm, and .... click, done

PS this is for the current GS version (mk 2). Not sure if this is also true for the mk1?