If you click on the cloud icon do they not download ?
I don't use iTunes Match, but to redownload items from the cloud you normally go to the Purchased section : click on your name/icon towards the top right of iTunes and then click Purchased on the popup e.g.
Or you can get to the Purchased section by clicking on the Purchased link under Quick Links on the right-hand side of the iTunes store homepage.
On the screen that you are taken to select Music (towards the top right), and clicking on the cloud icon on an album's top right corner, or to a song's far right if viewing Songs, should download it - if you want to download all of your music then you should have a Download All button button right