upvc multipoint

I'm hoping someone can help me with this. There must be a way to do it... I came home from holiday and couldn't open the front door (upvc multipoint lock). The key turns to a point, and then jams. My first thought was that someone try to snap it (it's an anti-snap pin), so I removed the handle...

The gearbox on my uPVC door failed, was a "GU case 35 old" style. I fitted a replacement and it works ok.... However the old one could be fully locked from either side simply by lifting the handle. If you didn't lift the handle the door could be opened from either side. Unlocking required a key...