Sorry, I've checked all of the likely places and I can't seem to find it at all.
Perhaps now would be a good time to invest in a Now TV Box with their 'Entertainment Package'? They are (if the recent offer's still on) just £16 at Asda or £20 (but with £2.70 worth of Clubcard points) at Tesco.
For that you get the box and 3 months access to ITVEncore, plus lots of other channels, such as GOLD, Sky 1, Sky Arts 1, Sky Atlantic, Comedy Central, etc, all through your internet connection. (There's no commitment to any type of subscription). It could be a nice little Christmas prezzie for yourself and you'd be able to see that missing episode of Broadchurch too.