Thanks again it's nice to here that confirmation on that that helped boat loads!! I had a feeling the rep was talking out her ass.
Absolutely she was .. I'd complain.
Wifi on your phone is exactly the same as wifi on a laptop .. if you have access to the network, you have 'free' data. In terms of access, there is no difference between devices on a wifi network unless the network admin puts them in. Theoretically, you could block phones on your own network .. but why? Rooting your phone makes no difference whatsoever.
Data from the phone provider, though (ie, 3G/4G/EDGE) is absolutely governed by them and they can charge by the bit if they like. Rooting your phone won't help because the information they require is on your SIM .. if the SIM matches an account on their network, you get data; if it does not, you have no connection.
The only warning I'd offer is that smartphones are dangerously addictive. Every single person I know who claimed smartphones were useless was hooked within days of owning one.