C7000vs2

I installed the nighthawk app last night. Now my wifi isn't working on any of my devices! My network connection is working, netgear says the hardware is working. But to use support I have to pay to get this fixed. I told netgear the issue started after the app but they still won't help unless we pay their fee. Huge scam!!!!
My wifi is on auto connect, it's not accepting the password which we didn't change. I try getting on the app to see if I can find the problem but the app won't work because the wifi isn't connected and working. Again... HUGE SCAM!
I did all the troubleshooting stuff like unplugged wifi. Then plugged back in, reset the modem, cleared cache.
I really need help, my 8 year old daughter needs the internet for school.