mjw5021, thank you for checking the settings. Rest assured that our only goal is to ensure that we resolve your concerns as we'd never attempt to charge you for more data than you used. Going back to the advanced settings for Wi-Fi in your phone. There is another settings showing, 'Keep Wi-Fi on during sleep'. Is this on or off? Lastly, you have the option to put your device in safe mode to temporarily disable all 3rd party applications to test the device to see if Wi-Fi stay connected. I would recommend keeping your device in safe mode a few hours and monitor it to see what happens. Click here for the steps to put your device in safe mode. http://spr.ly/65878CADR
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