You can't delete the account on your own, but you can ask the Ubuntu One support to do it for you, here.
Before asking them, you should read this entry on the FAQ that mentions all the details involved in deleting an account. Make sure you understand what accounts, websites, files and services will no longer be accessible for you, and if you still want to delete it, write to the support team mentioning that you don't mind losing access to everything attached to the account. Make sure you send your message from the email address of the account you want to delete.
You can't delete the account on your own, but you can ask the Ubuntu One support to do it for you, here.
Before asking them, you should read this entry on the FAQ that mentions all the details involved in deleting an account. Make sure you understand what accounts, websites, files and services will no longer be accessible for you, and if you still want to delete it, write to the support team mentioning that you don't mind losing access to everything attached to the account. Make sure you send your message from the email address of the account you want to delete.