You're doomed.
Best thing you can do at this point is to toss your 360 into an incinerator so they can't track you done and take legal action.
but at least you got a few achievements out of it, I'm sure it's worth it.
Didn't think of the consequences, because it's a glitch that could easily happen to anybody by accident. And I still don't own the games now- it only works with the MW2 demo.
I did it but just to test, I never got an achievement in any of the games but I don't think you have to worry about being banned but hopefully they fix it soon.
Few months ago there was a thread on gaf about stupid people on the xbox account support forum asking why there banned. A lot of stupid shit and there was someone who was banned for the Fifa 10 DLC glitch.
They did however ban people for the FIFA glitch. The Shadow Complex glitch was pretty much patched as soon as it was found and it doesn't give achievement points. It pretty much lets people complete the game in one-sitting, but they can't save or anything like that. Wasn't a big deal other than seeing the complete game/story for free.