billing

I am not sure what you mean by "billing".

I can see that last month you have asked: "How can I close my account?".

If you want to downgrade back to the free plan, you can do that from your Account's Billing page.

Complete Guide: How-to-Downgrade-Subscription-Back-to-Free-Account

If you want to delete an account, you can do it from profile section of your account.

Complete Guide: How-to-Delete-My-Account

Let us know if you need further assistance.