It appears you're writing about at least two different services and systems that normally don't interact: your AT&T Cell phone and your HughesNet Satellite Internet system. You may also be referring to a third service, a wired AT&T landline DSL Internet and telephone service on poles outside your house on the street? Very confusing. Again, this third service (DSL) is on a separate system and does not directly interact with the other two services.
Your AT&T cell phone cannot normally make cellular calls or send SMS text messages over a HughesNet satellite Internet connection. Those functions are normally not compatible with, nor can they connect through, your HughesNet satellite Internet system (unless, perhaps you have an iPhone running Apple's iMessage service, as mentioned in another recent topic on these forums: https://community.hughesnet.com/hughesnet/topics/problem-with-ipad-messaging-over-hughes-net-not-oth...
The reason your cell phone works in town but not at your house is probably because you have no cell signal at your house. Having HughesNet satellite Internet won't change that. If there is some minimal cell phone signal available outside your house, then you may be able to get a cell phone booster to help bring it inside the house.
HughesNet installers are not obligated or reimbursed to help you with your TV or your cell phone service, other than perhaps showing you how to connect your cell phone's Internet WiFi function to a HughesNet- or Installer-supplied wireless Internet router. Again, this normally won't help you make cell phone calls or send SMS text messages.
When you say you "left AT&T.com and went to HughesNet.com," are you referring to an AT&T wired DSL Internet service you had at another residence, before you moved to Oroville where you needed to get HughesNet service instead? Again, it's not clear the way you wrote it.
HughesNet and AT&T are not "doing battle over new territory." MagicJack may work over an AT&T DSL connection but probably won't work over a HughesNet connection due to the higher delay over satellite.