The lifthill cable (isn't it called cabel car?) needs to be exchanged as far as I know and this will take a while. But don't quote me on this. However, this is a recent problem that started a couple of days ago. On your day you just must have been very unlucky.
btw. forget checking their Social Media. They don't announce the closure anywhere. The only way to find out about it, is navigating to the ride's subpage on their website. There it simply says: Closed today