I have music on my iphone that redownloads everytime even though I don't want it anymore?

So I have some music that I purchased on my phone and I have since wanted them off my phone, I have tried deleting them off but every time I plug my phone into the computer they all redownload. I've gone to settings and everything and they are not checked off as songs that will download they aren't in any playlist I have and I have no clue how to make them stop downloading every time I plug my phone in.

In iTunes check the box for manual management.

1. Uninstall iTunes. Then grab the utility called Everything (linked in the source), install it, run it, give it time to index data (might take a few minutes) and then search for "itunes" (with or without quotes). Select all, delete it. Then reboot. Then reinstall iTunes from the apple website. If you are a Mac user, there should be a way to resetting itunes, same with itunes in windows if you don't want to uninstall and reinstall it.

ITunes should be asking you permission when you plug your phone in to do this. There's a small box that pops up during or before syncing that states that it's found purchased items on your phone that are not in your current library. It then offers you the option to have iTunes re-add them to your library or not to. If that option is not popping up, you might have told iTunes not to ask you anymore or you're simply not reading this warning all the way out of interest of time. Make sure you read everything that pops up next time you sync.

If nothing pops up, then a good option would also be to restore the ipod (using iTunes), delete the songs from your computer library, and then re-sync. This takes a while because it has to re-sync EVERYTHING since it deleted everything, but this should also solve your issue.

Diana B's option is also a good one, but I would recommend unchecking manual after you're done because it can be a pain long-term.