DNS Hijacking / Downgrading Gateway Firmware - Time Warner Internet

I'm a new customer to Time Warner and bought my own gateway. I have used OpenDNS for years, as I have children, and they offer free content filtering. I set my gateway up to use OpenDNS, but Time Warner keeps hijacking my DNS settings and reverting them back their own. I've been on the Internet, since 1995, and have never had an ISP force me to use their own DNS settings before now. Level 3 tech support claims not to know anything about it, but if one does some research, this has been going on for an eternity. How is this not a violation of net neutrality? Especially since I can go through and manually configure each wireless adapter to use OpenDNS. I shouldn't have to do that though when it can been done at the gateway itself.
As far as my gateway, when it was provisioned with Time Warner firmware, I lost some functionality. Some options that I had previously are no longer there. This was confirmed by my gateway manufacturer.
If these issues are not resolved I will file a formal complaint with the FCC. I hold an FCC license so I'm already familiar with navigating through their system. As long as my networking equipment doesn't cause interference to Time Warner's networking equipment, they should not have any say over where I route my DNS or what options my gateway has. It's as simple as that.