Hi,
Inorder to get the database backup, you'll have to login to your control panel and since your password has been reset, there's no way of doing it!! Without your password you won't be able to get into the shell either! I'm afraid, I don't see any other way out for you!
But if you don't mind, I'm very curious as to what provoked this kind of a situation! This is very frustrating indeed and I must admit that I've never seen such a situation before. Sites having problems or violating laws are usually suspended but the data is always handed back to the customers if they request for it. Anyway, best of luck to you and I hope things get better in time :-)
Regards,
Gabbar