You can get more useful answers on Samsung related forum. I ever found Samsung data loss questions. Many people recommend Vibosoft DR. Mobile for Android, you can have a try.
You cannot recover them. End of the sotry. And, please don't fall for spammers. Know the limits of the technology.
What about your device model? If it smart version then you can use few sms recovery apps and if it old model then there is no scope to recover that. You also can search in Google for more recovery informations.