I already reported the incident to Microsoft, and after about 3 weeks of investigation, I finally got my MS Points back. Luckily my credit card wasn't charged by the hackers, but to be safe I reported it stolen anyway and got a new one from my bank.
Now that I have my account back, I have a couple questions. I noticed that whomever hacked my account used my MS Points to buy Assassin's Creed 2, and got 3 achievements on the game. Those still show up on my account, and I don't want them to - it's not my game, I didn't earn the achievements, and now it's hindering my completion score since I have no interest in that game... it will affect my overall percentage of achievements earned. I called Xbox Live support immediately after I noticed this, but they weren't really able to help me, and suggested I ask here. If nobody here has any ideas, does anybody know an email address I can contact, like a more specialized support that deals with this sort of thing? During the investigation, I was never allowed to talk directly to the people who handled it, I was only able to find out through a generic service rep what the notes said.
Another question I had is about my credit card. The entire time I have had Xbox Live, I have used nothing but 12-month prepaid cards to get Gold. The only things I have ever used my credit card for were one-time purchases of games and MS Points... but when I try to remove my credit card from the account, both from my console and from the website, it says I can't remove it because there's a current subscription tied to it. WHAT subscription? It clearly says right there that my Gold is through a 12-month card... The support rep said he got the same luck and wasn't able to remove it. Now, since the card is now null and void, I'm not too concerned about somebody stealing it since it won't actually work... but I'd rather not have a non-working credit card on file, it just causes trouble if I do want to buy something.
Let me know if you guys can help!