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If your issue is with the WiFi then try this:
Go to you WiFi settings on your phone and delete your network, then turn off phone.
Turn off your router. Unplug from power. Wait 5 minutes, then turn back on.
Once router is fully rebooted, turn phone on and go back to your WiFi setting on your phone and sign into your network.
If your issue is with your data service, they could be working on the Towers. Call your network providers customer support for more info.