Internet problem escallation

I wanted 1 Gig internet.   I went to the Cox store and got the Cox modern / router.   After install, my speeds were brutally slow.    Cox decided that there was a physical problem with the Cable.  they came out and ran a new piece under the street and replace the cable into the house.   Then I get charged $100 for cox to replace their own hardware.    the tech even tried a replacement modem.   still it was 60% slower than advertised.   Anyway I digress,  speed with ethernet hard wire 105mbps,   with wifi 305mbps.     when  i call all i get is everything is good.......UGH!!!!!!!!!!!!!!!!!!!!!!!

Cox likes to tell me what I can do to fix such as take the router in and get a replacement.  I pay for service,  in this case $100 that was never disclosed to me (surprise!)

Canned responses and deflection does not  solve my service issues.  I need someone that can take action.