Right I have finally got round to getting a 360 to replace my venerable xbox but am having problems getting my live account onto it.

I signed it up ages ago and it was done on my parents credit card, problem is we can't find out what that card was and when it was billed last and the migration asks for the last 4 digits.

Is there anyway I can get this information from anywhere, either my old xbox or from Microsoft? I have emailed them (2 days ago) but have had no response.