This is happening to me over the last 6 months and they refuse to look into it and say that we use the data. We have unplugged the hotspot to make sure that there isn't anyone hacking the data. When the device is unplugged it continues to show data usage at 6:30 am when 1. nobody is in the office as this is a business hotspot and 2. the device has been turned off. Customer services has been a nightmare. They insist that we used our data and that we can upgrade. We have upgraded despite knowing that we aren't using the data, but I refuse to continue the upgrade as the data usage is not us. Tmobile needs to look into this because it's ridiculous.