Cant delete songs from my iPhone 4S!?

Ive bought some songs and a few albums over a period of 1 year. Every now and then, because the phone memory is not great, i delete old songs and update new ones, as one does. But the songs and albums i have purchased will not delete from the phone, at all. the other ones will delete, rearrange and these ones are like physically imprinted on my phone. Even so one album does not recognize it's in my phone that when i make an update it doubles up, so ill have two entries of the same songs, so this album of 22 songs now has 44 songs, 2 of the same entry song one after the other for 22 different songs.

How do i delete these songs? if i knew they'd physically imprint on my phone i would've never bought these songs, ever, i just want to delete them from my phone, they're taking up 5 GB memory..