If a reboot doesn't work, a call to DirecTV might. Nothing on the SAT channels may mean they somehow cancelled your service.
At some point a few years ago I mysteriously found myself with movie channels. I had not ordered them, There was no "free trial" going on. I called D*TV to make sure I wasn't paying for them. They said I or someone had ordered them using my online account with them. I hadn't. My wife hadn't. I asked if they could tell me when or how frequently my account had been accessed since I hadn't gone there in several months. In the end the agreed to cancel the movie channels and credit my account for any charges relating to them. They also gave me a new password for my D*TV.com account.
This also brings up an interesting question.... Can an HR20 be used as a PVR for local channels even if you cancel your D*TV service? Just curious.