It looks to me like Neilson have added a new 0870 number to their collection.
Their website http://sell-it.rwa-net.co.uk/home.jsp?benum=1281 lists a number 0870 0600114 which is different to the ones you have listed for them. I tried searching on this number and got no hits. So, I then tried searching on Neilson and found their entry on the 0870 database that way.
I just thought it might be worth adding this number to the database.
Cheers
Sarah