Wifi "unable to join network "networkname"" message after new software update 6.13 or whatever lol

I have been in contact with apple for over a week trying to solve this issue! We did a network reset, a factory reset, a router reset, a hard/soft reboot and nothing has worked. Apparently I am 36 days past my warranty on my 4s and they want me to pay them 200$ to fix it when I did nothing but upgrade my phone!

This is not my fault and refuse to pay for something they screwed up. I'm still in the mist of going back and worth with a supervisor about my issue.

Anyone try or do anything that solved the same issue?