One thing not made clear
As the phone connects to free wifi hotspots I assume the data usage is only when connected to and using the cell operators network.
If not then are they saying they will charge you for free data usage on free wifi ?
In Comparison BT Mobile offer non broadband customers a SIM only 12 month contract for £25, thats for unlimited calls and texts plus 20 GB of data, plus unlimited connection to BT Wifi with over 5 million hotspots and BT Sports. I have it and don't need home broadband or phone any more. Shows how bad a deal you get in the USA.