Auto Pay Issues

I've had auto payment setup from my savings account via account # and routing # since day 1 to get my auto payment discount.  My first auto payment went through with no issues.  The last 4 auto payments were denied and removed.  I reached out to Xfinity the past 3 times to sort it out, and it's been useless.  I've been 'assured' this won't happen again.  Low and behold it happened again.

Can someone actually figure out why this is happening???  Auto payment was set up to be mindless and yet there is no root cause to the issue.