Cox had changed their customer-support strategy within the past 10 years so instead of helping to resolve your issue, the reps instead try to sell you something. As you discovered, you had upgraded and rented everything but your issue remains.
First, I'd downgrade your plan to whichever you originally had. Next, I'd return the Panoramic WiFi and reinstall your previous gear. If you're on a contractual promotion, you should wait until it expires.
Calling Cox is usually hit or miss: sometimes you'll get sales; sometimes you'll get a techie. If you feel you've got sales, just hang-up, call back and hope for competency.
As for email, cox.help@cox.com with your Full Name, Complete Address and if you don't want to re-explain your issue, the URL of this post.