Remotes - DirecTV

I have a RCA DTV SLD40A45RQ-2015. I recently put Dish in my home and
I cannot for the life of me find a universal remote that works with my Dish
receiver and my RCA TV. The Dish remote works everything on my RCA TV
but the volume why is that? I've tried universal remotes, RCA remotes, nothing
Works the volume?????