How do I remove my TV remote from controlling the volume on my soundbar.

From that same settings menu Stuart suggested you go to, Settings > Room Settings > TV settings you can remove a remote control entirely from the PLAYBAR. 

If you're using the PLAYBAR as the speakers for your TV, we recommend turning off the TV speakers so you don't get an echo or have trouble with your PLAYBAR and TV audio getting out of sync. This would be done inside the TV's settings, selecting External Speakers for the Audio Output.
No sadly not. Just have standard Samsung remote

From that same settings menu Stuart suggested you go to, Settings > Room Settings > TV settings you can remove a remote control entirely from the PLAYBAR. 

If you're using the PLAYBAR as the speakers for your TV, we recommend turning off the TV speakers so you don't get an echo or have trouble with your PLAYBAR and TV audio getting out of sync. This would be done inside the TV's settings, selecting External Speakers for the Audio Output.
Try this to reset your remote:

Open the battery compartment on the back of the remote and remove both batteries.

Press and hold any button on the remote for 20 seconds.

Release the button and reinsert the batteries and the battery cover..

I had the same problem, and ended up reprogramming the playbar to map some seldom-used buttons on my remote to the volume + and - functions on the playbar. Not ideal, but mostly solves the problem.

I adore your system, guys. I first bought a 5 then it snowballed from there. No regrets, but is it possible for the system app to be updated so that if we change our minds from initially setting up the TV remote to control volume on the Playbar remove the option but we can still use our phones to do so?