I don't know if this has been brought up before - my thorough search into the archive has been inconclusive, so I assume I'm in the green zone.

What I want to enquire about is the topic's namesake. I've recently been having quite a bit of problems with Steam achievements that won't activate even when I acquire the specific item, defeat the boss, etc.
The game this has been happening to for me is Darksiders. I just bought it a few weeks ago - yeah, I was looking all over for the Hellbook Edition and only became a fan after playing the second game first.

Some of the achievements I'm missing include obtaining Ruin, defeating the Stygian and Straga and killing five Duskbats without touching the ground.

I would like to know if there's any way to fix this sort of problem, and if there's an alternate contact for Steam Support - the staff that's supposed to answer the questions are pretty much useless.

Kind regards and God bless.