I spent two weeks getting my password reset after I locked myself out for multiple incorrect password attempts.
Pretty much everything that could have gone wrong, did. I couldn't remember the answer to my security question, the option to send a password to my cell phone failed and after a week of wrestling with the Live ID support staff, they determined that I hadn't given them enough information to prove that I was me and locked my account permanently and stopped responding to my messages.
I called XBOX Live's support hotline once and they said there was nothing they could do, but they did update my credit card information which I thought was kind of odd.
A few days went by and no reply from the Live ID staff, so I called XBOX again and they gave me the holy grail, an actual telephone number to get in touch with Microsoft :O
I called the number and gave the tech my pin number associated with the issue thread I had started two weeks earlier and he said that he couldn't do anything personally but he'd re-escalate the thread to the Live ID group and they'd email me.
Two more days go by and then yesterday morning I opened my inbox and found that I'd had my account magically restored! With no further information given by me. So what changed in those two days to make them decide I was actually me, I don't know, but I have my account back and thought this might help others since I've seen multiple posts about this issue.
CALL THIS NUMBER IF THEY WONT HELP YOU: 1 800 642 7676
It worked for me anyway. Good luck.