How do I get Cox to Push a new firmware version to my Cable Modem

Hi,

I own my cable modem/ router, a NetGear C6300.  I've been happy with it, but recently my internet speeds have hit new lows.  I pay for 50 Mbps and am lucky to see 15 Mbps for a second or tow (burst) then it settles out at 3 maybe 4 if I am lucky.  I normally don't notice it, but relatives were visiting over the last week and with the 4 of us on the net, three of us were buffering while another watched low quality video.

Reading Netgear forums, they say the new firmware may help the problem, but Cox has to push the latest version.  Users can't update since we might push a bad software revision that hasn't been "tested".  The newest is 1.02.21, I currently am at 1.02.20.  

Ryan