You know, it almost sounds like the case you got isn't for the board you are going to use.
This may sound crazy, but a friend of mine in the UK got a Micronik Tower kit a few years back that fitted either an A600 or an A500 (I forget which)
He ended up having to sit the 1200 board outside for a while until he found someone to trade it to.
Can you take some screenshots of it?
If anything, maybe someone can help you better if we can see it. Perhaps you'll have to end up swapping it or maybe rebuilding something a little.
Just try not to get too impatient. Sometimes the simpliest things can be overlooked if you rush.
