Purchased songs no longer available

I had to restore my iPhone because i forgot my password to it, i ripped all the songs from the iPhone into a folder so i could keep them and just put them back when the restoring was finished and now i dont have the songs i purchased from iTunes and iTunes wont let me download them for free, it tells me "You have purchased this song before, would you like to purchase it again?" Help what do i do to get my songs i paid for before back?