Cusadmin password reset - hard reset fails

Hello, 

I tried to reset my cusadmin password to the default setting by doing a hard reset (pressing down the reset button button on the back of the router for more than 10 seconds)

I've tried this several times but the password is still not reset. I've also power cycled the modem several times. I've done the hard reset while it is off and then when it is on. It still does not default to the original password settings of highspeed or  CantTouchThis.  

We know for sure that the router is not getting hard reset because only one of the two bands are showing the 5 and not the 2.4 . 

Please can anyone help us do a hard reset properly? 

Thanks.