Did a little research about this comapany online, after they rudely called me at work and also at home on my mobile.
This is their address: Gm Connect Ltd. 6 Chatsworth Close, Blackburn, Lancashire, BB1 8QH.
This is a subsiduary of GM group, main address:
Suite 510, Daisyfield Business Centre
Appleby Street, Blackburn
Lancashire, BB1 3BL
Tel: 0870 850 4959
Fax: 0845 299 1421
Email: info@gmgroupltd.org
they are basically a "member" of the 3 group. Here is their spiel in their Company Overview on the GM group website: "Originally established as a contact centre selling mobile communications for UK’s fastest growing network Three, the GM Group has quickly developed within the industry by becoming the number one dealer for its distributor, achieving a quality status by becoming a selected member of the Three networks trusted Q-Club"
So that's where they got your number. If the telephone prefrence service cannot block them, then you either ask them to remove you from their database, or contact your mobile phone/landline service provider to get them to stop these calls coming through in the future. Their deals are rubbish anyway.
Hope this helps.