The device is up to date right?
Okay Is the app able to be deleted?
There is a way to cheat RCS features if the default Samsung app isn't working. You can download the Android Messages app from the Play store and then install. Once you're installed, you can go into the settings within Android Messages and enable RCS which should also push this into the stock Samsung messaging app. From there you can go into the Samsung app, enable RCS and then either keep or delete the Android Messages app. Give that a shot and let us know how things turn out.
I apologize for not getting back to everybody sooner, I actually didn't get to try the last suggestion. The RCS just started working again for some reason, not sure what happened but it works now.
If anything starts getting goofy, try out the suggestion above and let us know if it doesn't work out. We're more than glad to help troubleshoot with you!