A bit like Tesco's iPads
This whole story smells a little like the recent scandal with the Tesco offer to sell the new iPad 3 for £49.99
For those who don't know it, due to a 'computer'(?) error, Tesco advertised the wrong price (a 90% discount), a lot of people ordered - and were told that Tesco will not supply at this price. It is still hotly debated in the (social and mainstream) media.
In this case there isn't a price error - just a poorly designed promotion site where the O2 condition is buried in a separate PDF 'Terms and conditions' document (which, naturally, nobody reads) and is not mentioned anywhere on the actual promotion page. Many people - yours truly included - naively filled the form, only to be told they are not eligible.
Despite the 'Sony' domain, this is not Sony - they have their epic gaffes but cannot be so unprofessional. The UK promotion is outsourced (possibly by O2) to an outfit called 'Mad About Handling Ltd' run by a couple, Annabel and Angus Gilmour. Their 'professionalism' shines in that form and website - and in the subsequent handling of complaints.
Some victims may wish to run a retaliation campaign on Twitter and Facebook - like the Tesco crowd, who are currently causing serious reputation damage to the retailer. I wouldn't bother, though -