One or more of your assumptions are faulty.
Either your receiver is not set up correctly, or the TV is not performing correctly, or maybe you are on an HD channel presently showing SD programming, or maybe you are actually on an SD channel.
There is an ongoing dialog as to whether Dish or DirecTV has a better HD picture. Consensus seems to lean toward DirecTV being marginally better if any at all (some displays/programming make this irrelevant).
I have also heard that the Hopper/Joey system supposedly has a better picture than the earlier Dish receivers, but DVD quality, NEVER - if things are set up correctly.
I would look in the setup for the HDTV setup and make sure it is set to 1080i and 16X9.
If you indeed feel that the picture is inferior, call the installer. Only call Dish directly if you can't contact the installer. This has something to do with the way Dish pays and docks installers for installs and call backs. Well, he should have done it right the first time, so go ahead and call Dish about the problem.