If you'd like to close your account, go to the Account Settings > Billing page in PayWhirl and click the link at the bottom.
The system will prompt you to enter your password as a security measure before deleting your account. Closing your account will remove any and all data from the PayWhirl system. It isn't normally recommended, but you could also decide to delete your customers from your connected Payment Gateway.
Please let us know if we can be of any assistance, or if you have any suggestions to improve our experience.