Generalmente non è possibile riscaricare i brani acquistati da iTunes Store, ma questo link suggerisce che potrebbe esserci un modo per farlo, dopo tutto.
[...]But first, make absolutely sure that you don’t have any copies,
anywhere. It’s only prudent.
Once you are really sure that those iTunes songs are gone, here’s what
to do:
Open the iTunes Store on your device.
Make sure you are signed in with the same account used for the original purchase.
Tap Purchased from the bottom navigation bar.
From the Purchased tab, tap the artist name for the content you intend to download again.
Once you’ve located the music you are looking for, tap the download button.
(If you want to download all songs from an album that you’ve
purchased, click on the button to swith to the “Album” view.)
Potrebbe funzionare o meno per te, ma vale la pena provarlo.