A domain name can be removed instantly from an active account.
Right now, your account is suspended, which means you cannot remove the domain from your account.
Specifically, it’s suspended because it got too much traffic. This is also why we cannot let you remove the account or the domain name, because that would allow you to bring the website up right away on another account, which is the number one thing we definitely do not want you to do.
We cannot let you use our hosting and our subdomains when you want to if that involves overloading our servers. Which in your case, it does.