As said above, the problem from our end seems to have resolved itself. For future reference, if you purchase anything through xbox.com, whether it be MSP or Gold subscription it can take up to a few hours before the process is fully completed.
A work around is to do everything via your console as the transaction will be completed right there and then.
If you are still having problems with your account and it's still showing silver, delete your profile and recover it using the recovery system.
WĦo DaRεs W!ηs
Can I change my Gamertag for Free?