I have often had the same problem here in Denmark. It's strange that games are discontinued so soon after beeing released. Just a few years after the release of any game, it's practically impossible to find a store that carries it. In situations like this your only option is to order it online. Żour best bet is probably
amazon.co.uk. They're all used, and they're all shipped from UK, so the overall cost should be fairly low. I hope this helps.