turn on suggestions
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Hey 
Try this:
If you go to the SingStore and then in the bottom right go to 'My SingStore' and in here you will have 'Purchase History' can you see your songs in here?
If you can see them, highlight the song you want then press X to download it again.
Hopefully you will see the songs in this list and you should be able to download them again.
Fingers crossed!
