Hi
As far as i am aware the answer is yes,
IF you were allowed to take your mobile broadband abroad and use it in these countries then you would have been able to get the '3 like home prices'. If you think about it, a Mobile broadband device is just a phone without buttons or a bit to talk into but it still has a SIM and communicated with the network. It even sends SMS and i would imagine the price plan is just a data and SMS one but there is no reason why the billing platforms could not be modified to allow you to put that sim in a phone and use it. So you should have the same rights as a mobile phone user
Anyway i think you are now to late - i posted thìs in May over 1 month ago and i would imagine the window has closed. You could try, i would recommend writing to the chairman and address it to the Star House office - its on the 3 website if you find the company side of the site - google '3 uk company site'.
If you send letters to the Charmian they go to an executive complains department rather than just customer services, say you were not notified as you have not received the SMS but just found they are removing 3 like home and you were planning to go to italy for 3 months and thats one of the reasons you bought it but now they have change the T&C's you want out as its unfair.
I cant guarantee you will get out but you might as well try.