You will receive your 5,000 Credits each month on your monthly anniversary as long as your VIP Club membership is active.
To check, go to your Account Settings page and click on Change Avatar Name (located on the right side of the page under Account Tools).
That page will tell you how many Name Change Tokens you own.
If it has been more than 24 hours after your anniversary date, and you have still not received your NCT, please file a Help Ticket (Help If you subscribed using your Credit card or Pay Pal account, you don't have to do anything.
The VIP Club membership automatically renews each billing cycle (monthly, quarterly or yearly).
The membership fee will be billed to your Credit card or Pay Pal account.