I was deleting an album on my iTunes Match enabled Mac and I forgot to check the box that says, "Also Delete from Cloud" and I deleted the files themselves by not selecting "Keep Files." So now the album is entirely gone from my library and Mac but it is still in the cloud, able to be downloaded from my iPhone. How must one delete music from the cloud so it may not count towards the 25,000 song limit?
Login to your iTunes Account in iTunes! On the right hand side, there is a menu where you can click on a button which says: "Bought Content" (i'm a German User). There you have a list of all your media bought on iTunes!
Download your Music which you want to delete again, and then delete it correctly on your Mac!