xbox live subscriptions being taken on an expired card.

In order to remove your payment method from your XBOX Live account 3 conditions need to be met.

• Automatic Renewal needs to be turned off. To learn how to do this click
  here.
  
• Your account cannot have an XBOX Live Gold Subscription on it.
• You cannot have any sort of billing/payment violations on the account (ie: past due payments/expired credit card)
  

If your card is expired, you will need to add a new payment method before being able to remove the old expired card.

https://commerce.microsoft.com

The link above will show you your current subscriptions with microsoft and there is a link at the top called payment options manage your payment card. once your card expires it does not cancel your xbox live. For example, my card has expired a couple of
months ago but my xbox live subscription expires in 2014.

1. You are correct that you should never display any of your account/personal information.

2. This is what I understand from your post. If you applied an Xbox Gold subscription card on the 6th, and your account renewal/"expires on" date is on the 18th, then the credit card would not be charged. At least that's how it has worked
for me.

You can verify by clicking on your gamertag name in the upper right corner of this web page, then "Microsoft Account" and then click the "Services & Subscriptions" tab, you will see a date that your Xbox Live subscription expires on. If the date is something
beyond February 18, 2016, then your Xbox Live Gold subscription card has taken effect and the credit card should not be charged at that time.

Hi there! Unfortunately, if your subscription expired due to a card no longer being active, you may need to provide another credit card that is not expired. You can do this by going on XBOX.com or on your XBOX Live.

By XBOX.com:

1. Scroll up to your gamertag and click on My Account.

2. Click on Update/Renew and provide your Windows Live ID and password.

3. Update your card information. That's it!!!

By XBOX Live:

1. Press the Guide button and scroll left to Account Information.

2. Provide your card information. That's it as well!!!

In my Services & subscriptions page I can see:

Subscription

Prepaid 3M Xbox LIVE Gold

Expires on

3/24/2016

Paid with

Prepaid card