found this in the iphone terms of my existing contract, i assume it is the same in all other existing ones.
Quote:
“8.4 You may end this Agreement by giving us written notice if:
[LIST=1][*]we break this Agreement in any material way and we do not correct the situation within 7 days of receipt of your written request;[*]we go into liquidation or a Receiver is appointed over our assets; or[*]we increase charges for calls, messages or data that form part of your inclusive allowance or your Line Rental Charges, or change this Agreement to your significant disadvantage, in accordance with paragraph 9.2 of the General Terms, provided you give us a minimum of 30 days' written notice (and provided you notify us within one month of our telling you about the changes). This does not apply where the increase or change relates solely to Additional Services in which case you may cancel, or stop using, that Additional Service[/LIST].”
I would guess we wont see our unlimited data removed until we upgrade.