Wow. Just wow. MS you are a joke.
You realize why they do it though right? For years MS has been fighting off the moding community and people playing burned/leaked copies of games like Halo or Gears. Before MS caught onto modded DVD firmware it was easiest to 'flag' people most likely suspect by who was playing games before they released to retail. Leaked copies of games go online often weeks before retail release. MS just sits back and waits for the hordes of 'hackers' to pop in their copy and sign into Live.. then Bam! Flagged for a ban.
I even think MS went as far as to update the Live ToS a few years ago to say they can terminate consoles/gamertags if they are suspect of violating the ToS, which I think indicates not playing games before release dates. I'll have to see if I can dig it up..
But if the ToS clearly states it, and the OP agreed to the ToS (which he did).. MS has every right to act how they choose. They do it thin out the hackers and modded consoles connected to Live. They do not do it to be assholes and not let people play games early.
edit. In all my years I have never once heard of a console or gamertag being unbanned so the OP was probably SOL from the get go, regardless of GAF connections.