Help downloading OS X Mountain Lion

Hi,

We have purchased OS X Mountain Lion and we cant seem to download it. It was purchased back in december but I shouldnt think this should be an issue.

Basically, when we go onto the app store and go to our puchased items, the OS X Mountain Lion is there and it says download, but when you click download, a little spinny thing comes up for about 6 seconds, then disappears and nothing happens.

Alternatively, if you try to click the title 'Mountain Lion', it says that "This item is currently unavailable in UK stores".

Can anyone help us with this??

Sarah