3DS + Pokemon Platinum troubles

[geetry]

So today my friend gave me her copy of Platinum since she doesn't use it. I put it in my 3ds only to discover at first that my ds wouldn't read the game. I cleaned the contacts, didn't help. I then turned off my ds, turned it back on, and the game was there.

When I launched the game, whenever I would click start on Giratina's screen, I'd get a communication error saying like "If you were in the union room, you'll be returned there, please press the A button. Whenever I did press the A button, I'd get a white screen and nothing would happen from there. Even trying to reset the save file would lead to this screen.

I looked it up, the only results I found were "it's a rom/pirated" and I know that's not the case. My friend was able to use the game perfectly fine, she has the same exact DS I do. I'm not sure if it's my DS or if it's my game...I don't have another DS to test it out on, so I really can't tell you.

I also took the game out and tried putting it back in, now it won't read it again. I turned it off, but this time it won't read it whatsoever.

I'm just bummed and looking for a fix, I've been looking forward to playing this all day.