I had this same issue, and thought I was going to have to do Comp Wins to get the Match Coin.
The thing is, mission drops have a limit per week, similar to item drops.
So just wait the next week, go to regular servers, and get mission drops. That's what I did, even though I had a Comp Wins in Mist mission (still have to finish it).
YOu still have until Oct. 2nd to finish all your missions, which still is a good 4 weeks, so roughly 20 mission drops to get that gold coin.
Ok, I found the answer, and it's a weird one.
Basically, it was Time Machine's fault.
I use TM as my backup mechanism, but I back my system to an external HD. So, I naturally assumed that my backups were all exclusively on that external HD.
Nope.
Time Machine takes liberties with the free space on your system partition. It uses as much free space as it thinks it can to store a local backup, known as "snapshots". It does this as a safety net measure, in case you need to back your system up and you don't have access to the external hard drive where the main backup is maintained.
What happened (I'm not 100% sure, but I think it's a good enough guess to personally accept it as an answer) is that, when I deleted large files such as Borderlands 2, CS:GO, and even iPhoto (good riddance), Time Machine saw more available space for its snapshots, and used it accordingly. As deleted from here, Time Machine used the space there.
And here was I, thinking my SSD was broken because it was reporting my free space wrong.
Anyway, how to "fix" it?
By disabling this weird and obscure (though possibly helpful) Time Machine behavior. This article explains it in detail, but basically you just type sudo tmutil disablelocal into the Terminal and approve the command using your system password. This disables the snapshots feature, and you're left with only the external HD backups — as I thought was the case all along. (And yes, the article says Mac OS X Lion, but it's the same on Mavericks or Yosemite.)
That's it. I'm potentially less backed up now in case of an emergency, but now I have more available disk space than I know what to do with.
Guess I'm redownloading CS:GO...
Best Answer
As far as I can tell only your last eight matches are available to download from within cs:go.
Matches you downloaded are saved to your local machine and are simply on your harddrive. Of course you can copy those to another harddrive, but you will not be able to download older matches than the last eight matches again.