In all likelyhood there will be no way to get your data back via 'professional' or otherwise, unless you have a backup. Almost certainly this will be a public key encryption, which means that without the private key the criminals have, a 'professional' would need access to a major super-computer for a significant amount of time. And they still would probably fail. If you work for GCHQ then you might have an angle, but otherwise give up before some 'professional' takes a lot of money from you for an eventual lost cause. Horrible though it is, your data is gone. All you can do now is wipe and learn to keep backups. Sorry, but to say otherwise is to mislead. Forget suggested protection software, if you back up properly there's no point.