router username and password

my service was installed Thursday, I was able to login to the panoramic router, I made no changes, just wanted to look at settings, I have been in the IT industry for 22 years, I wanted to look at the firewall settings and MAC filtering options, but again made no changes, was busy and had to go, today I tried to login several times and can no longer get in with the default admin password.  Does COX ever login and change these? my concern some has hacked it, I now see several devices connected that I cannot identify, if I reset the unit, not reboot, but reset, will I need COX to reconfigure it?  If someone else has the password it will do me no good to just reset the wireless password, they will just change it