Same thing happened to me. I kept on hitting the cartridge, and after doing so, I got my data back. Until I was out with my parents, then a glitch occurred, when I was playing Hector's Story normal mode. And after it occurred, when I went back to the main menu, it said "New Game" and "Resume Game", with nothing saying "Restart Chapter, Copy File, Erase File, and Extras".I kept my progress however, but my extras data was erased. (My Sound Room access and my unlocked songs, locked again. Support conversation viewer, only an "A" support between Gietz and Fiora, as well as Farina and Dart left to go for unlocking all of them.)
It's gonna be very rare to buy a brand new copy of it.