Remote issues

The power button, volume and mute button on my remote stopped working.  I contacted Xfinity customer service and we went through all the steps to troubleshoot the problem.  They finally decided that I needed a new remote.  I went to the Xfinity store and got a new remote.  Went through all of the steps to pair the remote to my TV.  It did not work.  All of the other buttons on the remote work except the TV won't turn off with the power button, the mute button doesn't work and the volume button doesn't work.  Any ideas as to how to fix this problem?