button reset not clearing admin tool username and password

I changed the username and password for the admin tool to access the modem via 10.0.0.1 and have long forgotten it.  The only information in the Xfinity forums and troubleshooting advise to hold the WPS button down until the light on the front flashes.  (the amount of time for holding the button varies depending on which page you're reading. anywhere from 30 to 60 seconds and all sorts of lead you nowhere other options).  

When I perform the reset, the only thing it does is clear out my wifi network and password and restores those to the default which are shown on a sticker on the bottom.  The sticker DOES NOT show any admin username and password for the admin tool and the same tired answer of "it should be 'admin' with the password as 'password'" DOES NOT work. 

Is there a different default password for accessing the admin tool via a browser?  I purchased a very expensive router and I want to put the router in bridge mode but I cannot get past the username and password.