My cox internet keeps dropping connection!

For a little over a week now my internet has been dropping connection on all devices in my apartment, wired and wireless. I called cox and the first representative claimed that my issue was that my modem was “unhealthy” even though I’ve had it for less than a year. I have a net gear nighthawk C7000v2 which is a very expensive router. So I replaced my modem with a brand new net gear night hawk, but I’m still having the same problem. I then replaced all Ethernet cables and bought a new co-ax cable and the issue still is happening. I’ve called and talked to multiple 6+ representatives and texted with about 10+ others and no one has been able to do anything and they even refuse to send out a technician because there connection is good on there end and are blaming my equipment. Does anyone have any suggestions or should I just cut my losses and cancel my cox subscription??