N64 Deleted save files??

Deleted save files?

Hey all, I need some help. I was playing Paper Mario yesterday, basically when I decided to stop, I turned the system off and turned it back on to see my save file erased. Today, I started over and made it all the way to Dry Dry Ruins, turned it off, and just now turned it back on to see my files deleted again. Now because I was so anxious of losing my data again, every time I would save, I would restart the console and my files would be there. But when I fully turned it off and back on hours later, my file was gone. So it seems it’s able to save, but turning it off deletes the file. Is this a problem with the system or the cartridge?? Can I get my file back?? Please help!