Grahame
https://forums.adobe.com/message/5766518#5766518
Have a look at this Adobe forum thread. It has some more detail from a staff member about why this is happening. It doesn't refer to Photoshop but the situation
might apply for all Adobe products. Basically they seem to be asking for an email, mailing and credit card registered in the same country as the Adobe store. Items 3, 4, and 6 of the thread refer.
I presume, but don't know, that if someone in an unsupported country also met those mail and credit card requirements in a
second location which
was in a supported country it would work for initial registration. But what would happen when you had to do the 90 day re-registration? And what would happen when an update within the 90 days was due to be downloaded via the CC update app? Would you need to go to that second country to do those tasks, or could you re-register and download from the unsupported country (Fiji in your case). In other words, is it just a mail/credit card issue, or is it also a geographical/internet issue?
I'd ring Adobe customer support as Mark suggests above, and perhaps put this scenario to them. Do you have a relative in a supported country who could act as your proxy base?
EDIT - Another interesting thing is what happens if I took my laptop with CC installed down to Fiji for a month (that sounds nice!) and my 90 days were due, or I wanted to download some new updates for the product - would it let me in Fiji?