Suspended for No Reason

for information about your suspension and to see about submitting a case review, you would need to go to
http://enforcement.xbox.com Keep in mind that investigations do take time so suspensions are not necessarily issued the same time as the action.So it could be for something that was done weeks ago.

If you are on a child account you would need to have the parental account log into the site Daft has linked for them to view and file a case review for you.

although the answer is almost a year old, it stays the same, please see hassassinades message

Please post in
forums.xbox.com/.../41.aspx and a XBLPET will be with you quickly. Though in my personal opinion the card could've had enough money but when the tried to finally charge it was a void card. At most you'll need to call in and get this fixed unless the XBLPET's
can fix this issue.

You don't get suspended for no reason. Why would Microsoft do that? If you get suspended, the appropriate team (enforcement I think) look into it and if you did nothing they won't ban you

If you want to appeal a ban, you have to submit a case review at http://enforcement.xbox.com