because last year they had a loyal customer policy that if you had original iphone which was in 18month contract, you could upgrade to 3G without paying an upgrade fee
and this year they have scrapped it...
Yeeeeees because as has been explained a hundred times before, last time you upgraded or broke your contract to start a new 18 month contract because you had bought outright an unsubsidised 1st Gen iPhone.
Now, you are locked into a 18 month contract with O2 which includes a subsidised 3G iPhone…
O2 have to recoup the money on the iPhone.
Therefore you cannot upgrade early, unless you "buy yourself out"…
Which is why some of us didn't upgrade back then and held on to our 1st Gen iPhones to be able to upgrade this year.
Simple.