If you have the Arris DG950 Modem/Router Combo you can log into it just like a regular router. type in the IP Address in any browser (Default IP 192.168.0.1) and type in the username and password if you don't know what those are they may be default which is
Username: admin Password: password
If you cant get into the console i'm not sure who you would call to get them reset. most likely the standard customer care number.
The tech came and couldn't figure it out. Told me to hook up my router, which I had earlier told him made it so I did have internet. He said the modem needed replaced but they probably didn't have any in the warehouse.
After he left, I hard reset the modem (unplug coax, hold reset button down for 15 secs) and now it works as it should.