Nest won’t connect to my WiFi

[Adriana1211]

My nest Will not connect to the Wi-Fi. I have already uninstalled it and reinstalled it and it will not connect. I have troubleshoot it all week long. Who can I speak to in regards to getting my nest replaced? 

[Frustratedddd]

How old is the thermostat, and who installed? Ie retailer/you/Nest Pro Installer?