I've read the problem you already posted (no WAN) and this is exactly NOT the same as yours, unless you ordered a Business account and got Residential.
Let me understand this correctly: Your devices can connect to the modem via wifi, but can't get out to the internet?
1. Is any of the devices connected to wifi able to go to http://192.168.0.1?
2. Can you get out to the internet if you use a LAN cable with your computer?
Check http://192.168.0.1/index.html#!/home/status to see if you have RSS of 15. Regardless, I suggest you unplug the modem from power and disconnect the coax for a minute. Then reconnect the coax and then add power. Maybe you can gety back online. There seems to be many causes of the SQF15 error that can be cured with the coax dance.