Anyone know how I can block the Cox customer who is constantly attacking my router?

Hi folks,

I'm a Cox Platinum customer and I can normally surf the web at pretty decent speeds. Lately though, I've been getting attacked by about 16 other computers simultaneously (all with COX ip addresses) and things slow down drastically when this happens. My router was attacked for 2 hours straight tonight and it's getting a little old, night after night. Complaining to abuse@cox.net didn't seem to do any good. Anyone have any ideas how I can stop these attacks?

       Thanks,

             DanG