changing country on apple billing profile

I'm from the UK and am working in Thailand for 3 months over the summer.

I wanted to buy an app but was todl that my card had expired a while ago (it's been a long time since I bought an app)

So I logged in to chance my billing address details and card to discover that for some miraculous reason, apple in all their widsom have decided that I'm from the USA yet despite having a British mobile number. I basically need to change my country to the UK, but the country changing option isn't available of the profile edit section.

Has anyone else had a similar problem with their profile? If so, how did you get to change your country?

any feedback would be appreciated

cheers