Why have your credit card in the first place when Microsoft points are sold at everywhere from Walmart to corner stores? Needless risk.
If you're gonna use one to buy your gold account, just cancel it immediately and you'll get free gold until the card was meant to expire anyway haha
Taking away your credit card seems pretty much impossible. I use time cards so I cancelled the auto-renewal, but it still says the credit card is being used for Xbox Live and cannot be deleted or something like that.
Yeah that's how I discovered this. When I first got my X-Box I didn't have a CC so I used my mom's to sign up for Live, but she kept getting annoyed at me buying points with it and paying her back so she asked me to delete it. I didn't ever manage to figure out how, so she simply cancelled the credit card outright. Then when it came time for my Live to auto-renew, it did, but since the card was cancelled, nobody actually got charged for it. They have a system for recognizing expired cards, but not cancelled ones, it seems.