Cannot delete FTP accounts with special characters

I have some FTP accounts that I can't delete because theirs names contain special characters (&é"'(--)), these accounts are created via API calls so cPanel didn't valid the account names.

I have tried to set quota to zero but without success (normally it works for deleting anonymous accounts), can you please tell me how to remove these accounts (I have accessto both cPanel and WHM).

Thanks.

 

Thanks for your suggestion but I don't have root access to the server.