Be Patient, How long as the site been up? When you start getting traffic it will generally then start to show. It is gathered by users visiting your site with the alexa bar installed on their browser, so they need to gather a fair bit of data!
Hi Alexa rank increase only by using the Alexa toolbar and if you want to increase it in uk then start working for UK sites to get the traffic.
just give it some time.. it will grow.. you cant get Apples from Apple tree within a month.. just do on page seo. and be active in social world, comment on blogs, doesnt matter Do follow No follow.. just comment.. and slowly it will raise,