ecoplus oscillating wall mounted fan

Hey guys, I'm having a bit of a problem with these wall mounted fans. I'm trying to tilt it down, and it will not stay in place. It keeps forcing itself bake up. Is there any trick to this or something I'm missing?

LOL.
Pics?
If you have it mounted right, it should oscillate, but stay at the vertical angle you set it to.

bump mine is doing the same.