Promoting Xbox Live account in an Adult account.?

[jShazBot]

For too long I've been using other accounts to download M rated demos or videos with mature content on Xbox Live.
I just turned 17 and I was hoping that now I'm at the legal age to play M rated games I would possibly have the option to download videos and M rated games now but I still can't!
I also want to opt-in to the newest Xbox Live news and Advertisements on the dashboard but I can't because technically I'm still a Child Account. Everyone tells me that I have to go the Manage Profile and select "Promote Child Account" but that option is nowhere to be found. I've even changed the Windows Live ID associated with my gamertag to one that has a much older age logged into it and I still can't get my gamertag adult privileges.
I originally made my gamertag when I was about 13 or 14 and on the original Xbox. At that time, you were required to enter in a credit card and date of birth. Because I was much younger, I used my moms Credit Card and Email and she also made me enter in my actual age.
Now, when I got my Xbox 360 on September 26th, 2007 I had to recover my account and in doing so I had to associate my gamertag with a "Parent email" (One which I quickly made in a minute just so I could get past the initial setup). Although that password for this email still works when I have to enter it in every time I want to access Xbox Live controls in the settings, the actual @live.com email address for it doesn't even work anymore when I try to log into it on the computer. In these Xbox Live and console settings it gives me the option to allow downloading M rated games and even when I set it to approve, I still can't download M rated demos on the market place or opt in to the advertisements.

Everyone I know who had a problem being stuck with a Child account all say they were able to fix this by simply entering the Promote to Adult account option an option I don't have.

This has been bothering me for a long time but now I'm very concerned because I just found out that Facebook, Twitter, and Last FM can only be used by ADULT accounts as well.