Seems to be a case of they register an interest in your number and you then receive a text message letting you know they are requesting it, so it's not as bad as a lot of people are making out when it comes to it.
If you do want to unsubscribe though it seems pretty simple but it must be done before the beginning of next week to make sure that you are ex-directory.
To remove your number click on the link below, you need your mobile phone with you to do this as they text you a code
1, http://www.118800.co.uk/
2, Click on ‘Ex Directory’ at top right hand side of page, from there it’s straight forward.
