Devices won’t connect to internet please help

So my internet isn’t working anymore. I’ve tried talking to customer service they can’t fix the problem. It was working just fine until yesterday morning people started randomly being about to connect to my home network. I’d pause the devices but our connection speed became slow and the eventually uncooperative. The customer service attempted restarting the gateway, it didn’t work. Then we tried switching modems that didn’t work. Then they had me factory reset the modem which then won’t let any of my devices connect to the internet even with Ethernet. My web browsers keep redirecting me to the 10.0.0.1 admin login which never loads. I just see a spinning circle, I’ve tried clearing browser history and cookies. I’ve tried restarting the modem and even switching back to my old modem. I’ve tried trouble shooting my computer as well, but my boyfriends computer has the same thing going on. I tried connecting to WiFi on my PlayStation 4 it wouldn’t work, for some reason only my phone works with the WiFi.

Someone please help me I’m at a loss and I’m super stressed out. I understand it’s not the customer services fault for the issues I just want this to be resolved please.