Hello Aaron, Thank you for contacting Steam Support. Our records indicate that your purchase was declined due to your current IP address differing from what is on file with your billing information. We have removed the lock on your account - you will now be able to purchase additional subscriptions. Additionally, please try your purchase again by launching Internet Explorer or Firefox and using this link:
http://store.steampowered.com/?cc=uk Please let us know if you have any questions, or if you encounter any further difficulty.