Can't delete a specific song on my iPhone?

I bought it on iTunes a really long time ago and I can't delete it no matter what I try… I've even tried restoring my phone to get rid of it and switched computers to a different itune but its not even in my itunes library… Normally I really wouldn't care but everytime I plug my phone into my car radio it plays the song unless I go on my phone and pick a song. Everytime. It does it if I press next on my radio too or sometimes it just skips and starts playing it. Its like a freaking ghost song no joke. Can anyone help?

Find the song listed in the music app on your phone and, while still on the list, swipe from right to left and the option to delete that one specific song will appear.