Ah... don't think there's a way to manually turn it off unless you ask your telco to remove internet service (BB data plan?) from your plan.
edit: if you don't have a BB data plan and not incur internet service charges, change your browser to hotspot so it'll use your Wifi and change the apps to use Wifi (if they allow this).
Every carrier now requires u to have a data plan with any smartphone unless you are grandfathered in. So unless you are grandfathered in, you wont be able to cancel your data plan.
Every carrier now requires u to have a data plan with any smartphone unless you are grandfathered in. So unless you are grandfathered in, you wont be able to cancel your data plan.
TMobile doesn't currently require a data plan unless you purchase a subsidized phone.
And many carriers outside the US also do not require a data plan currently.